SPX sessions closed in positive gamma, with the net-gamma percentile 50 to 80, on Treasury auction days

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

73 of 1,122 sessions match. Of them 100% closed above the flip (archive 56%) and the mean open-to-close move was 0.67% (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
2026-10-017,666.87-0.02%7,658.0+8.8709Claims, ISM, Housing, EIA, Auctions
2026-09-037,747.40+0.62%7,721.6+25.8706Claims, ISM, EIA, Auctions
2026-06-097,386.10-0.86%7,357.7+28.4758Auctions, Fed
2026-05-287,563.45+0.59%7,556.1+7.4605PCE, Housing, GDP, Claims, EIA, Auctions
2026-05-207,432.50+0.79%7,409.2+23.3707EIA, Auctions
2026-02-266,908.31-0.45%6,897.1+11.2755Claims, Fed, EIA, Auctions
2026-01-136,963.52-0.27%6,956.6+6.95320CPI, Housing, Auctions
2025-12-226,878.40+0.18%6,873.5+4.9746Auctions
2025-12-086,846.39-0.42%6,842.2+4.27912Auctions
2025-11-196,642.05+0.31%6,637.2+4.9759VIX settlement, EIA, Auctions
2025-10-286,891.30+0.03%6,887.1+4.27512Confidence, Auctions
2025-10-226,699.45-0.50%6,699.0+0.45521VIX settlement, EIA, Auctions
2025-10-086,754.17+0.45%6,745.6+8.5656VIX settlement, EIA, Auctions
2025-09-256,604.25+0.08%6,599.2+5.17031Housing, GDP, Claims, EIA, Auctions
2025-08-286,502.27+0.16%6,490.0+12.37018GDP, Claims, EIA, Auctions
2025-08-276,482.14+0.36%6,476.2+6.0600VIX settlement, EIA, Auctions
2025-08-266,466.07+0.50%6,445.3+20.76019Housing, Confidence, Auctions
2025-08-206,395.92-0.15%6,381.4+14.55513VIX settlement, EIA, Auctions
2025-07-096,262.72+0.19%6,247.8+14.95812VIX settlement, EIA, Auctions
2025-06-256,092.50-0.21%6,091.5+1.15014Housing, VIX settlement, Fed, EIA, Auctions
2025-06-246,093.90+0.48%6,083.9+10.0750Fed, Confidence, Auctions
2025-05-295,911.99-0.40%5,905.9+6.16032GDP, Claims, EIA, Auctions
2025-04-225,287.57+1.51%5,266.2+21.4708Auctions
2025-04-095,454.52+10.00%5,080.3+374.26014VIX settlement, EIA, Auctions
2025-02-126,051.72+0.75%6,042.9+8.85011CPI, VIX settlement, Fed, EIA, Auctions
2025-02-116,068.62+0.34%6,062.0+6.6558Fed, Auctions
2025-01-276,012.80+0.47%5,994.4+18.47921Housing, Auctions
2025-01-085,917.37+0.25%5,905.5+11.87913Claims, VIX settlement, EIA, Auctions
2024-12-266,037.31+0.23%6,033.9+3.4612Claims, EIA, Auctions
2024-12-235,972.75+0.52%5,947.8+24.9634Housing, Auctions, Fed
2024-11-255,986.10-0.27%5,983.9+2.27030Auctions
2024-11-205,916.71+0.04%5,886.6+30.27014VIX settlement, Fed, EIA, Auctions
2024-10-085,752.05+0.53%5,735.2+16.8750Auctions
2024-09-265,746.17-0.25%5,741.8+4.45514Housing, GDP, Claims, EIA, Auctions
2024-09-115,554.32+1.29%5,472.2+82.1704CPI, VIX settlement, EIA, Auctions
2024-09-105,497.12+0.12%5,476.9+20.26510Auctions
2024-08-215,620.07+0.19%5,611.7+8.46526NFP, VIX settlement, EIA, Auctions
2024-07-105,633.92+0.76%5,601.0+32.9632VIX settlement, EIA, Auctions
2024-06-265,478.66+0.39%5,464.6+14.1753Housing, VIX settlement, EIA, Auctions, Fed
2024-06-185,486.66+0.16%5,480.3+6.45016Retail sales, VIX settlement, Auctions
2024-05-285,306.14-0.09%5,301.6+4.65523Confidence, Auctions
2024-04-105,161.75+0.23%5,157.4+4.46519CPI, VIX settlement, EIA, Auctions
2024-03-275,248.17+0.24%5,225.8+22.47512VIX settlement, EIA, Auctions
2024-03-115,118.62+0.07%5,114.0+4.65014Auctions
2024-02-214,981.46+0.33%4,961.1+20.35531VIX settlement, Auctions
2023-12-124,642.97+0.55%4,632.2+10.8745CPI, Auctions
2023-12-114,623.30+0.54%4,612.4+10.97417Auctions
2023-11-204,548.36+0.77%4,534.1+14.3500Auctions
2023-11-084,383.87-0.05%4,378.0+5.95512VIX settlement, EIA, Auctions
2023-10-114,377.70+0.06%4,362.3+15.4608PPI, VIX settlement, Auctions
2023-09-284,298.86+0.73%4,296.4+2.56024GDP, Claims, EIA, Auctions
2023-08-294,498.77+1.48%4,473.9+24.9750Confidence, JOLTS, Auctions
2023-06-284,377.60+0.24%4,371.7+5.97034VIX settlement, EIA, Auctions, Fed
2023-06-274,378.60+0.84%4,355.5+23.1552Housing, Confidence, Auctions, Halts
2023-05-254,151.32+0.18%4,144.5+6.87013GDP, Claims, EIA, Auctions
2023-05-244,115.62-0.28%4,115.2+0.45515VIX settlement, EIA, Auctions
2023-05-174,158.57+0.71%4,136.8+21.8756Housing, VIX settlement, EIA, Auctions
2023-05-104,137.22-0.31%4,126.0+11.2506CPI, VIX settlement, EIA, Auctions
2023-04-274,135.57+1.37%4,102.6+33.0651GDP, Claims, EIA, Auctions
2023-04-194,154.52+0.40%4,149.2+5.36516VIX settlement, EIA, Auctions
2023-04-134,146.20+1.03%4,126.8+19.4652PPI, Claims, EIA, Auctions
2023-03-294,027.37+0.42%4,014.7+12.76016VIX settlement, EIA, Auctions
2023-03-083,992.42+0.04%3,983.1+9.36022JOLTS, EIA, Auctions
2023-02-234,012.80-0.20%4,001.1+11.75014GDP, Claims, EIA, Auctions
2023-01-254,015.00+1.15%3,988.5+26.5751VIX settlement, EIA, Auctions
2023-01-123,983.75+0.11%3,979.5+4.36012CPI, Claims, EIA, Auctions
2022-12-293,848.02+0.98%3,846.5+1.5503Claims, EIA, Auctions
2022-10-193,696.65-0.22%3,694.4+2.36010Housing, VIX settlement, EIA, Auctions
2022-10-133,670.01+4.81%3,574.9+95.1751CPI, Claims, EIA, Auctions
2022-09-124,110.17+0.48%4,105.3+4.87528Auctions
2022-07-203,959.29+0.69%3,954.1+5.25012VIX settlement, EIA, Auctions
2022-05-264,058.55+1.67%4,052.3+6.3650GDP, Claims, EIA, Auctions, Fed
2022-05-253,978.00+1.23%3,968.7+9.35016Housing, 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.