SPX sessions closed in negative gamma, with the net-gamma percentile 50 to 80

60 sessions · the archive filtered by the dealer book · all sessions · the calendar

60 of 1,122 sessions match. Of them 0% closed above the flip (archive 56%) and the mean open-to-close move was 0.57% (archive 0.59%).

Every row is a finished SPX session and links to its page, where the same numbers stand with the day's events and a free minute-by-minute replay. The filters are the closing measurements those pages print: the zero-gamma flip against the close and the open, the net-gamma percentile, how often the flip was crossed, and the calendar event the day carried. The shares above are counts over the matched days next to the same counts over the whole archive; a share that matches the archive is a base rate, not a pattern.

SessionCloseMoveFlipvs flipPctlCrossEvents
2026-10-027,722.25-0.10%7,722.3-0.17015NFP, Housing
2026-09-167,551.90-0.71%7,580.0-28.17013Retail sales, VIX settlement, EIA, FOMC
2026-09-097,636.50-0.22%7,643.7-7.27033VIX settlement, Auctions
2026-08-217,673.55+0.02%7,676.7-3.15034Opex
2026-08-067,709.60-0.21%7,715.7-6.15028Claims, EIA
2026-07-247,410.80-0.01%7,422.2-11.45012Housing
2026-07-077,503.17-0.39%7,504.8-1.75512Auctions
2026-04-106,816.69-0.31%6,820.4-3.75017CPI, Housing, UMich
2026-04-016,574.47+0.13%6,584.7-10.27523Retail sales, VIX settlement, ISM, EIA
2026-03-306,344.00-1.19%6,369.2-25.2605Fed
2026-02-236,837.67-1.01%6,839.5-1.8505Housing
2026-02-186,880.55+0.46%6,888.1-7.6759Housing, VIX settlement, Auctions
2026-02-036,917.89-1.02%6,924.3-6.4608
2026-01-286,977.09-0.29%6,979.2-2.1658VIX settlement, EIA, FOMC
2025-12-156,816.60-0.65%6,821.4-4.86313
2025-11-266,812.45+0.26%6,816.9-4.5553Housing, Claims, VIX settlement, EIA, Auctions, Fed
2025-11-216,602.80+0.46%6,611.9-9.16015Fed, Opex
2025-11-036,851.32-0.32%6,852.2-0.95525ISM, Fed, Refunding
2025-10-316,841.65-0.40%6,845.8-4.26526
2025-07-086,226.07-0.10%6,227.3-1.25336Auctions
2025-06-205,968.07-0.66%5,972.7-4.6653EIA, Opex
2025-06-166,032.42+0.28%6,032.6-0.25514Auctions
2025-05-095,660.15-0.46%5,662.5-2.46532UMich
2025-04-084,987.15-4.77%5,082.6-95.5503Auctions
2025-03-205,662.02+0.48%5,668.6-6.6508Claims, EIA
2025-03-125,600.19-0.49%5,603.1-2.95021CPI, VIX settlement, EIA, Auctions
2025-01-065,974.64-0.20%5,987.1-12.5748Housing, ISM, Auctions
2025-01-025,868.42-0.82%5,871.1-2.66820Claims, ISM, Housing, EIA
2024-12-315,883.81-0.71%5,889.8-6.05323VIX settlement, Confidence
2024-09-175,634.01-0.40%5,636.6-2.65010Retail sales, Auctions
2024-08-125,343.62-0.26%5,344.2-0.57512
2024-08-055,187.74+1.20%5,201.7-14.06521ISM, Fed
2024-08-015,445.16-1.80%5,461.4-16.2585Claims, ISM, Housing, EIA
2024-07-315,522.19+0.37%5,524.4-2.26311Refunding, VIX settlement, EIA, FOMC
2024-07-305,436.27-0.75%5,438.8-2.6537Confidence, JOLTS
2024-07-265,459.37+0.47%5,460.3-0.95313PCE, UMich
2024-05-135,221.52-0.30%5,222.2-0.76524
2024-05-075,188.77-0.00%5,189.3-0.5706Auctions
2024-05-015,020.27-0.22%5,055.1-34.8608Refunding, VIX settlement, ISM, JOLTS, Housing, EIA, FOMC
2024-04-125,122.80-0.74%5,131.7-8.9559UMich
2024-01-264,890.10-0.05%4,891.2-1.17518PCE, UMich
2023-11-134,411.12+0.17%4,412.7-1.6506
2023-11-074,378.87+0.30%4,378.9-0.16510Auctions
2023-10-034,229.89-0.89%4,235.4-5.56511JOLTS
2023-09-134,467.50+0.01%4,470.2-2.75017CPI, VIX settlement, EIA, Auctions
2023-08-224,387.54-0.64%4,393.3-5.85010
2023-08-114,463.11+0.36%4,463.2-0.16527PPI, UMich
2023-07-244,554.77+0.08%4,555.4-0.6538
2023-03-223,936.62-1.62%3,997.2-60.65024VIX settlement, EIA, FOMC
2022-12-203,821.55+0.36%3,825.4-3.86311Housing
2022-11-083,828.07+0.35%3,829.8-1.85513
2022-10-123,578.17-0.20%3,592.0-13.85032PPI, VIX settlement, Auctions
2022-10-113,587.80-0.17%3,603.9-16.1508
2022-10-103,613.57-1.00%3,619.0-5.55027
2022-09-063,909.44-0.82%3,918.3-8.96010ISM
2022-08-194,230.02-0.63%4,232.9-2.97511Opex
2022-06-163,665.62-0.99%3,672.6-7.0551Housing, Claims, EIA
2022-05-164,007.44-0.06%4,016.8-9.35320
2022-05-104,001.87-1.59%4,010.9-9.06413
2022-05-034,173.47+0.40%4,174.8-1.37021Housing, JOLTS

Turn a filter into a rule

A count is where a question starts. The Lab takes a rule in plain words ("sell the 0DTE straddle at 10:00 on days that opened below the flip with the percentile under 20"), compiles it against every archived session and reports the out-of-sample verdict with day-clustered intervals. An assistant with the MCP server can page through the same archive with list_sessions and get_session.

Measurements are model output derived from public trade and quote data; they are approximations and can be wrong. Nothing here is investment advice; see the Terms.