{
 "DESCRIPTIVE_BANNER": "DESCRIPTIVE / OBSERVABLE - book-state census over top-of-book quote tapes. A locked book (ask == bid) is a ZERO QUOTED SPREAD and is COUNTED, never repaired; a crossed book (ask < bid) is COUNTED and EXCLUDED from the reduction, never repaired. Neither is a transaction cost, an edge, a verdict or a graduation. The defect-versus-behaviour cut is asserted ONLY in the absent case, which needs no threshold; where locked books are present this artifact reports their STRUCTURE and returns NOT ESTABLISHED.",
 "classification_rule": {
  "ABSENT": "zero locked rows; needs no threshold; the only verdict asserted",
  "INSUFFICIENT": "fewer than 1000 usable rows",
  "PRESENT": "locked rows occurred; structure reported, cut NOT established",
  "declared_before_reading": true
 },
 "corpus_reading": "ABSENT ACROSS THE CORPUS - zero locked books in 21,158,845 rows over 16 root(s). On this feed, in this window, a zero quoted spread did not occur.",
 "kind": "hades-quote-book-census",
 "kind_label": "book-state census - zero-spread and crossed books, measured at source",
 "max_rows_per_root": 9000000,
 "measured_utc": "2026-08-23T01:59:43Z",
 "min_rows": 1000,
 "per_root": [
  {
   "bars": {
    "buckets_seen": 1378,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1377,
    "qualified": 1377,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 1.637,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 715050,
    "rows_unparseable_skipped": 0
   },
   "root": "6A",
   "rows_in": 715049,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 79858,
     "150000": 69,
     "200000": 24,
     "250000": 22,
     "300000": 12,
     "50000": 635064
    },
    "distinct_values": 6,
    "exact": true,
    "max": 300000,
    "min": 50000,
    "total_rows_counted": 715049,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 715,049 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1379,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1378,
    "qualified": 1378,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 2.253,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 739946,
    "rows_unparseable_skipped": 0
   },
   "root": "6B",
   "rows_in": 739945,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 622142,
     "1000000": 6,
     "200000": 117625,
     "300000": 71,
     "400000": 14,
     "500000": 32,
     "600000": 16,
     "700000": 15,
     "800000": 17,
     "900000": 7
    },
    "distinct_values": 10,
    "exact": true,
    "max": 1000000,
    "min": 100000,
    "total_rows_counted": 739945,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 739,945 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1376,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1375,
    "qualified": 1375,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 1.875,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 481701,
    "rows_unparseable_skipped": 0
   },
   "root": "6C",
   "rows_in": 481700,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 37654,
     "150000": 11,
     "200000": 27,
     "250000": 2,
     "50000": 444006
    },
    "distinct_values": 5,
    "exact": true,
    "max": 250000,
    "min": 50000,
    "total_rows_counted": 481700,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 481,700 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1380,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1379,
    "qualified": 1379,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 4.977,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 1191700,
    "rows_unparseable_skipped": 0
   },
   "root": "6E",
   "rows_in": 1191699,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 151326,
     "150000": 146,
     "200000": 120,
     "250000": 45,
     "300000": 35,
     "350000": 15,
     "400000": 8,
     "50000": 1039992,
     "500000": 5,
     "550000": 2,
     "650000": 1,
     "700000": 4
    },
    "distinct_values": 12,
    "exact": true,
    "max": 700000,
    "min": 50000,
    "total_rows_counted": 1191699,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 1,191,699 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1380,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1379,
    "qualified": 1379,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 3.932,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 1012490,
    "rows_unparseable_skipped": 0
   },
   "root": "6J",
   "rows_in": 1012489,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "1000": 105874,
     "1500": 29,
     "2000": 8,
     "3000": 1,
     "500": 906577
    },
    "distinct_values": 5,
    "exact": true,
    "max": 3000,
    "min": 500,
    "total_rows_counted": 1012489,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 1,012,489 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1373,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1372,
    "qualified": 1372,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 2.046,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 519855,
    "rows_unparseable_skipped": 0
   },
   "root": "6N",
   "rows_in": 519854,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 122388,
     "150000": 53,
     "200000": 2,
     "250000": 4,
     "300000": 4,
     "350000": 5,
     "400000": 16,
     "50000": 397382
    },
    "distinct_values": 8,
    "exact": true,
    "max": 400000,
    "min": 50000,
    "total_rows_counted": 519854,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 519,854 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1374,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1373,
    "qualified": 1373,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 1.662,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 402770,
    "rows_unparseable_skipped": 0
   },
   "root": "6S",
   "rows_in": 402769,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000": 265553,
     "150000": 53618,
     "200000": 4378,
     "250000": 177,
     "300000": 37,
     "350000": 31,
     "400000": 7,
     "450000": 8,
     "50000": 78944,
     "500000": 7,
     "550000": 3,
     "600000": 3,
     "650000": 2,
     "800000": 1
    },
    "distinct_values": 14,
    "exact": true,
    "max": 800000,
    "min": 50000,
    "total_rows_counted": 402769,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 402,769 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1378,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1377,
    "qualified": 1377,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 1
   },
   "elapsed_s": 6.566,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 1534282,
    "rows_unparseable_skipped": 0
   },
   "root": "CL",
   "rows_in": 1534281,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "10000000": 970744,
     "100000000": 16,
     "110000000": 10,
     "120000000": 1,
     "130000000": 4,
     "140000000": 4,
     "160000000": 1,
     "180000000": 1,
     "20000000": 545455,
     "30000000": 15158,
     "40000000": 1680,
     "50000000": 536,
     "60000000": 165,
     "70000000": 287,
     "80000000": 24,
     "90000000": 194
    },
    "distinct_values": 16,
    "exact": true,
    "max": 180000000,
    "min": 10000000,
    "total_rows_counted": 1534280,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 1,534,281 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1381,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1380,
    "qualified": 1380,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 22.927,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 5378125,
    "rows_unparseable_skipped": 0
   },
   "root": "ES",
   "rows_in": 5378124,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "1000000000": 342,
     "1250000000": 123,
     "1500000000": 43,
     "1750000000": 32,
     "2000000000": 7,
     "250000000": 5093750,
     "500000000": 282610,
     "750000000": 1217
    },
    "distinct_values": 8,
    "exact": true,
    "max": 2000000000,
    "min": 250000000,
    "total_rows_counted": 5378124,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 5,378,124 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1381,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1380,
    "qualified": 1380,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 1
   },
   "elapsed_s": 8.714,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 2103072,
    "rows_unparseable_skipped": 0
   },
   "root": "GC",
   "rows_in": 2103071,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "100000000": 52717,
     "1000000000": 652,
     "1100000000": 398,
     "1200000000": 271,
     "19000000000": 1,
     "200000000": 328135,
     "300000000": 979930,
     "400000000": 619171,
     "4200000000": 8,
     "4300000000": 4,
     "4400000000": 5,
     "4500000000": 4,
     "4600000000": 5,
     "4800000000": 3,
     "4900000000": 3,
     "500000000": 98336,
     "5000000000": 6,
     "5100000000": 1,
     "5900000000": 5,
     "600000000": 14773,
     "6000000000": 1,
     "700000000": 3551,
     "800000000": 1726,
     "900000000": 1099
    },
    "distinct_values": 53,
    "exact": false,
    "max": 19000000000,
    "min": 100000000,
    "total_rows_counted": 2103070,
    "truncation_note": "more than 24 distinct spread values; the narrowest and widest 12 are carried and the middle is NOT represented"
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 2,103,071 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1376,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1375,
    "qualified": 1375,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 1
   },
   "elapsed_s": 1.616,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 381895,
    "rows_unparseable_skipped": 0
   },
   "root": "HG",
   "rows_in": 381894,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "1000000": 236959,
     "10000000": 75,
     "10500000": 55,
     "11000000": 46,
     "11500000": 30,
     "12000000": 30,
     "12500000": 6,
     "13000000": 4,
     "13500000": 3,
     "14000000": 1,
     "1500000": 90028,
     "2000000": 3001,
     "2500000": 496,
     "3000000": 184,
     "3500000": 50,
     "4000000": 37,
     "43500000": 1,
     "4500000": 17,
     "500000": 50180,
     "5000000": 13,
     "5500000": 4,
     "6000000": 7,
     "9000000": 150,
     "9500000": 122
    },
    "distinct_values": 29,
    "exact": false,
    "max": 43500000,
    "min": 500000,
    "total_rows_counted": 381893,
    "truncation_note": "more than 24 distinct spread values; the narrowest and widest 12 are carried and the middle is NOT represented"
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 381,894 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1319,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1318,
    "qualified": 1318,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 1.639,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 370473,
    "rows_unparseable_skipped": 0
   },
   "root": "NG",
   "rows_in": 370472,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "1000000": 290821,
     "2000000": 78705,
     "3000000": 701,
     "4000000": 112,
     "5000000": 39,
     "6000000": 45,
     "7000000": 33,
     "8000000": 13,
     "9000000": 3
    },
    "distinct_values": 9,
    "exact": true,
    "max": 9000000,
    "min": 1000000,
    "total_rows_counted": 370472,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 370,472 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1356,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1355,
    "qualified": 1355,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 1.173,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 265538,
    "rows_unparseable_skipped": 0
   },
   "root": "NKD",
   "rows_in": 265537,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "10000000000": 94816,
     "100000000000": 100,
     "105000000000": 53,
     "110000000000": 57,
     "115000000000": 46,
     "120000000000": 25,
     "125000000000": 10,
     "130000000000": 1,
     "140000000000": 3,
     "15000000000": 92742,
     "20000000000": 24616,
     "25000000000": 19361,
     "30000000000": 10545,
     "35000000000": 6076,
     "40000000000": 3920,
     "45000000000": 3162,
     "5000000000": 2659,
     "50000000000": 2356,
     "55000000000": 1419,
     "60000000000": 1213,
     "80000000000": 233,
     "85000000000": 176,
     "90000000000": 117,
     "95000000000": 95
    },
    "distinct_values": 27,
    "exact": false,
    "max": 140000000000,
    "min": 5000000000,
    "total_rows_counted": 265537,
    "truncation_note": "more than 24 distinct spread values; the narrowest and widest 12 are carried and the middle is NOT represented"
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 265,537 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1380,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1379,
    "qualified": 1379,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 1
   },
   "elapsed_s": 3.441,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 848513,
    "rows_unparseable_skipped": 0
   },
   "root": "SI",
   "rows_in": 848512,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "10000000": 146507,
     "15000000": 399895,
     "170000000": 19,
     "175000000": 11,
     "180000000": 10,
     "185000000": 10,
     "190000000": 4,
     "195000000": 8,
     "20000000": 235365,
     "200000000": 5,
     "205000000": 1,
     "210000000": 5,
     "215000000": 1,
     "220000000": 1,
     "25000000": 40118,
     "30000000": 5698,
     "35000000": 1529,
     "40000000": 615,
     "45000000": 265,
     "5000000": 17608,
     "50000000": 134,
     "500000000": 1,
     "55000000": 61,
     "60000000": 41
    },
    "distinct_values": 45,
    "exact": false,
    "max": 500000000,
    "min": 5000000,
    "total_rows_counted": 848511,
    "truncation_note": "more than 24 distinct spread values; the narrowest and widest 12 are carried and the middle is NOT represented"
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 848,512 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "bars": {
    "buckets_seen": 1353,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1352,
    "qualified": 1352,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 11.922,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 2954666,
    "rows_unparseable_skipped": 0
   },
   "root": "SR3",
   "rows_in": 2954665,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "2500000": 2942607,
     "5000000": 12058
    },
    "distinct_values": 2,
    "exact": true,
    "max": 5000000,
    "min": 2500000,
    "total_rows_counted": 2954665,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 2,954,665 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  },
  {
   "reason": "INSUFFICIENT: 0 usable rows is below the declared MIN_ROWS=1000; absence over a handful of rows is not evidence of absence.",
   "root": "TIO",
   "rows_in": 0,
   "usable": false
  },
  {
   "bars": {
    "buckets_seen": 1377,
    "contract_rule": "ENFORCED \u2014 every quote row carries its contract, so a bucket straddling a roll is refused. (The exchange ohlcv-1s path cannot run this rule; this one can, and this count is real.)",
    "m1_bars": 1376,
    "qualified": 1376,
    "refused_contract_split": 0,
    "refused_hole_overlap": 0,
    "refused_in_progress": 1,
    "refused_weekend": 0
   },
   "crossed": {
    "buckets_emptied_by_exclusion": 0,
    "note": "crossed books are COUNTED and EXCLUDED, never repaired",
    "rows_excluded": 0
   },
   "elapsed_s": 9.099,
   "fx_day": "2026-08-20",
   "locked_note": "ask == bid rows are KEPT (their mid is exactly that value) and their zero spread shows on spread_min. On a carry-forward-merged tape a locked book is a merge artefact, so spread_min == 0 is NOT a quoted spread and must never be read as zero transaction cost.",
   "read": {
    "exceeded_row_cap": false,
    "lines_read": 2258785,
    "rows_unparseable_skipped": 0
   },
   "root": "ZN",
   "rows_in": 2258784,
   "scale_divisor": 1000000000,
   "schema": "mbp-1",
   "spread_raw_histogram": {
    "counts": {
     "15625000": 2254738,
     "31250000": 4046
    },
    "distinct_values": 2,
    "exact": true,
    "max": 31250000,
    "min": 15625000,
    "total_rows_counted": 2258784,
    "truncation_note": null
   },
   "tape_header_note": "second-venue anchor tape - rows are {t: ts_event_ms, b, a, c: contract}; one-sided books are COUNTED in the segment summary, never written as quotes",
   "usable": true,
   "volume": "this bar is derived from a QUOTE tape (mbp-1 top-of-book), which records book updates and not trades: there is no traded volume in the input to sum. No volume field is emitted, and 0 is deliberately NOT emitted \u2014 a zero would render as 'nothing traded this minute', which is a claim the input cannot support. Read the exchange ohlcv-1s feed for traded volume.",
   "zero_spread": {
    "distinct_minutes_with_lock": 0,
    "fraction_of_rows": 0.0,
    "locked_rows": 0,
    "longest_run": 0,
    "reading": "no locked book in 2,258,784 rows - a zero quoted spread did not occur on this feed in this window. This verdict needs no threshold.",
    "runs": 0,
    "share_in_longest_run": null,
    "verdict": "ABSENT"
   }
  }
 ],
 "publication_note": "Published derivative. Removed: the data vendor's dataset identifier and our internal tape file paths. Altered: nothing else - every count, verdict, histogram and reading is carried through verbatim from the measurement artifact. The venue is the exchange the prices traded on; the feed they arrived over is not the subject of this measurement.",
 "roots_seen": 17,
 "roots_usable": 16,
 "total_crossed_rows": 4,
 "total_locked_rows": 0,
 "total_rows": 21158845
}