SPX sessions closed in negative gamma, with the net-gamma percentile 20 to 50, on VIX settlement days

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

54 of 1,122 sessions match. Of them 0% closed above the flip (archive 56%) and the mean open-to-close move was 0.63% (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
2026-09-307,651.51-0.55%7,700.1-48.6455PCE, GDP, Fed, VIX settlement, EIA
2026-08-127,748.52-0.17%7,750.6-2.03522CPI, VIX settlement, EIA, Auctions
2026-07-017,483.35+0.14%7,497.6-14.23015VIX settlement, ISM, Housing, EIA
2026-06-247,358.75-0.22%7,374.9-16.2458Housing, VIX settlement, EIA, Auctions, Fed
2026-06-177,420.70-1.31%7,478.2-57.4359Retail sales, VIX settlement, EIA, FOMC
2026-06-107,267.52-1.08%7,317.1-49.6353CPI, VIX settlement, EIA, Auctions
2026-05-197,354.17-0.17%7,364.8-10.72022VIX settlement
2026-03-256,591.77-0.45%6,598.7-6.92531VIX settlement, EIA, Auctions
2026-02-116,942.22-0.68%6,949.1-6.83539NFP, VIX settlement, EIA, Auctions
2026-02-046,882.81-0.55%6,888.1-5.24523Refunding, VIX settlement, ISM, EIA, Fed
2026-01-076,921.37-0.33%6,944.7-23.33711Housing, VIX settlement, JOLTS, EIA
2025-11-056,796.75+0.35%6,812.5-15.8252Refunding, VIX settlement, ISM, EIA
2025-10-156,670.77-0.21%6,673.6-2.8309VIX settlement, Fed
2025-09-106,532.62-0.07%6,534.1-1.42012PPI, VIX settlement, EIA, Auctions
2025-07-306,362.67-0.20%6,368.9-6.22112GDP, Refunding, VIX settlement, EIA, FOMC
2025-06-116,022.71-0.40%6,035.1-12.44012CPI, VIX settlement, EIA, Auctions
2025-04-235,377.07-0.77%5,390.9-13.8305Housing, VIX settlement, EIA, Auctions, Fed
2025-04-165,274.90-1.27%5,286.8-11.94013Retail sales, VIX settlement, EIA, Auctions, Fed
2025-03-265,712.15-1.12%5,733.0-20.8253Housing, VIX settlement, EIA, Auctions
2025-03-185,614.57-0.60%5,616.3-1.72036Housing, VIX settlement, Auctions
2025-02-265,956.42-0.15%5,969.4-13.0405Housing, VIX settlement, EIA, Auctions
2025-01-296,038.10-0.31%6,040.5-2.44527VIX settlement, EIA, FOMC
2025-01-226,086.39+0.18%6,089.9-3.5261VIX settlement, Auctions
2024-12-185,872.81-2.88%6,008.0-135.2321Housing, VIX settlement, EIA, FOMC
2024-11-275,997.97-0.24%5,999.1-1.14525PCE, Housing, GDP, Claims, VIX settlement, EIA, Auctions
2024-11-135,986.47-0.07%5,992.7-6.22015CPI, VIX settlement
2024-10-235,796.62-0.64%5,796.7-0.12517VIX settlement, EIA, Auctions
2024-09-255,721.32-0.33%5,724.0-2.74514Housing, VIX settlement, EIA, Auctions
2024-09-185,618.30-0.34%5,636.8-18.53021Housing, VIX settlement, EIA, FOMC
2024-09-045,520.47+0.15%5,523.2-2.73526Housing, VIX settlement, JOLTS
2024-08-285,592.71-0.59%5,593.7-1.04523VIX settlement, EIA, Auctions
2024-07-175,589.10-0.40%5,596.6-7.53212Housing, VIX settlement, EIA, Auctions
2024-06-125,420.71+0.02%5,424.6-3.9357CPI, VIX settlement, EIA, FOMC
2024-04-175,022.95-0.98%5,036.8-13.9308VIX settlement, EIA, Auctions
2024-04-035,212.30+0.31%5,217.9-5.6258VIX settlement, ISM, EIA
2024-03-065,104.87-0.14%5,108.2-3.33019Fed, VIX settlement, JOLTS, EIA
2023-11-224,556.65-0.05%4,556.7-0.03517Housing, Claims, VIX settlement, EIA
2023-11-154,503.47-0.13%4,509.0-5.52527PPI, Retail sales, VIX settlement, EIA
2023-10-254,186.77-0.99%4,199.0-12.2256Housing, VIX settlement, EIA, Auctions
2023-09-204,401.82-1.15%4,439.9-38.13518VIX settlement, EIA, FOMC
2023-07-124,471.84-0.12%4,474.6-2.83715CPI, VIX settlement, EIA, Auctions
2023-07-054,446.82+0.22%4,446.9-0.0267Housing, VIX settlement, EIA
2023-06-214,365.75-0.17%4,372.1-6.33024Fed, VIX settlement, Auctions
2023-05-034,091.15-0.85%4,119.2-28.02515Refunding, VIX settlement, ISM, EIA, FOMC
2023-02-223,989.80-0.33%3,993.8-4.02018VIX settlement, Auctions
2023-02-084,119.07-0.61%4,124.8-5.73011VIX settlement, EIA, Auctions
2022-12-143,997.90-0.60%4,006.1-8.24210VIX settlement, EIA, FOMC
2022-12-073,934.77+0.00%3,936.7-2.04738VIX settlement, EIA
2022-11-163,960.30-0.40%3,967.2-6.93024Retail sales, VIX settlement, EIA, Auctions
2022-11-023,760.95-2.27%3,829.5-68.62511Refunding, VIX settlement, EIA, FOMC
2022-09-213,790.82-2.29%3,857.7-66.93025VIX settlement, EIA, FOMC
2022-06-223,760.65+1.10%3,770.5-9.8255Fed, VIX settlement, Auctions
2022-05-183,924.20-2.87%3,972.4-48.2262Housing, VIX settlement, EIA, Auctions
2022-05-113,934.19-1.40%3,987.5-53.33313CPI, VIX settlement, EIA, Auctions

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.