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

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

81 of 1,122 sessions match. Of them 100% closed above the flip (archive 56%) and the mean open-to-close move was 0.51% (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
2026-09-247,704.75+0.46%7,693.4+11.41005Housing, Claims, EIA, Auctions
2026-09-177,637.80-0.04%7,634.0+3.99014Housing, Claims, EIA, Auctions
2026-08-277,731.24+0.35%7,718.8+12.410016Claims, EIA, Auctions
2026-08-257,677.27-0.03%7,669.0+8.39523Housing, Confidence, Auctions
2026-08-137,798.82+0.41%7,792.0+6.9904PPI, Claims, EIA, Auctions
2026-07-087,482.92+0.34%7,466.2+16.7909VIX settlement, EIA, Auctions
2026-06-117,393.92+1.35%7,327.1+66.88034PPI, Claims, EIA, Fed, Auctions
2026-05-267,519.02+0.03%7,513.4+5.68517Confidence, Auctions
2026-05-127,400.75+0.18%7,372.9+27.9857CPI, Auctions
2026-04-096,825.15+0.81%6,808.5+16.71008PCE, GDP, Claims, EIA, Auctions
2026-04-086,782.20-0.06%6,771.5+10.78514VIX settlement, EIA, Auctions
2026-04-076,617.42+0.42%6,573.9+43.6805Housing, Auctions
2026-03-116,775.15-0.24%6,767.3+7.810026CPI, VIX settlement, EIA, Auctions
2026-02-256,946.55+0.31%6,935.9+10.7850VIX settlement, EIA, Auctions
2026-01-296,967.37-0.31%6,934.3+33.19010Housing, Claims, EIA, Auctions
2025-12-246,932.00+0.35%6,916.6+15.4950Claims, VIX settlement, EIA, Auctions
2025-12-236,909.75+0.42%6,893.2+16.51004PCE, Housing, GDP, Auctions
2025-12-116,900.94+0.63%6,878.9+22.01009Claims, EIA, Auctions
2025-11-256,766.32+1.03%6,737.6+28.81007PPI, Retail sales, Confidence, Auctions
2025-11-246,705.67+0.92%6,693.9+11.8800Auctions
2025-11-106,832.77+0.54%6,807.5+25.3802Auctions
2025-10-276,875.15+0.36%6,857.1+18.0950Auctions
2025-10-096,734.67-0.35%6,729.0+5.71006Fed, EIA, Auctions
2025-09-096,513.07+0.23%6,501.7+11.38520Auctions
2025-08-066,344.97+0.63%6,335.0+10.0857VIX settlement, EIA, Auctions
2025-07-286,389.72-0.11%6,386.4+3.410028Auctions, Refunding
2025-07-106,279.57+0.26%6,273.7+5.9846Claims, EIA, Auctions
2025-06-266,141.37+0.44%6,130.0+11.4802Housing, GDP, Claims, EIA, Auctions
2025-06-126,044.70+0.55%6,035.2+9.51007PPI, Claims, EIA, Fed, Auctions
2025-06-106,038.80+0.40%6,023.4+15.41004Auctions
2025-05-275,921.17+0.80%5,906.7+14.4954Housing, Confidence, Auctions
2025-04-245,484.65+1.96%5,455.5+29.2950Housing, Claims, EIA, Auctions
2025-03-255,776.52-0.02%5,768.5+8.08030Housing, Confidence, Auctions
2025-02-196,144.07+0.47%6,127.6+16.5956Housing, VIX settlement, Auctions
2025-02-136,115.14+0.86%6,079.8+35.41002PPI, Claims, EIA, Auctions
2025-01-286,067.06+0.70%6,047.7+19.3806Housing, Confidence, Auctions
2024-12-246,037.27+0.92%6,006.1+31.2950VIX settlement, Auctions
2024-12-176,050.05+0.07%6,046.5+3.610013Retail sales, Auctions
2024-11-266,021.37+0.34%6,007.9+13.59512Housing, Confidence, Auctions
2024-11-065,929.60+0.55%5,910.0+19.610010VIX settlement, EIA, Auctions
2024-11-055,782.72+0.96%5,764.1+18.61000ISM, Auctions
2024-10-095,793.82+0.81%5,773.6+20.2801VIX settlement, EIA, Auctions
2024-09-125,594.92+0.76%5,573.5+21.48010PPI, Claims, EIA, Fed, Auctions
2024-08-085,321.16+1.23%5,301.0+20.1950Claims, EIA, Auctions
2024-06-135,434.07-0.01%5,424.0+10.18514PPI, Claims, EIA, Auctions
2024-06-115,375.57+0.60%5,348.8+26.8902Auctions
2024-06-105,360.55+0.42%5,350.4+10.21002Auctions
2024-05-095,213.76+0.44%5,202.3+11.5952Claims, EIA, Auctions
2024-05-085,187.87+0.33%5,183.4+4.5808VIX settlement, EIA, Auctions
2024-04-255,048.87+0.82%5,029.2+19.69011GDP, Claims, EIA, Auctions
2024-04-245,072.77-0.13%5,068.2+4.68018Housing, VIX settlement, EIA, Auctions
2024-04-115,198.86+0.52%5,176.9+22.08510PPI, Claims, EIA, Auctions
2024-04-095,209.79-0.22%5,189.3+20.51009Auctions
2024-03-195,177.35+0.75%5,161.9+15.4807Housing, Auctions
2024-03-125,175.49+0.65%5,160.7+14.8858CPI, Auctions
2024-02-275,079.15+0.08%5,070.1+9.1908Housing, VIX settlement, Confidence, Auctions
2024-02-074,994.87+0.35%4,989.1+5.8956VIX settlement, EIA, Auctions
2024-01-254,894.47+0.18%4,884.0+10.58521Housing, GDP, Claims, EIA, Auctions
2024-01-174,739.26+0.12%4,730.5+8.79031Retail sales, VIX settlement, Auctions
2024-01-114,780.09-0.29%4,767.8+12.31006CPI, Claims, EIA, Auctions
2024-01-104,782.60+0.47%4,768.9+13.7954NFP, VIX settlement, EIA, Auctions
2024-01-094,755.17+0.41%4,749.9+5.310011Auctions
2023-12-274,781.84+0.16%4,774.7+7.18032VIX settlement, Auctions
2023-11-284,554.30+0.19%4,552.0+2.310025Confidence, Auctions
2023-09-274,274.12-0.34%4,269.4+4.78013Housing, VIX settlement, EIA, Auctions
2023-09-194,444.30+0.02%4,437.1+7.2956Housing, Auctions
2023-08-284,434.07+0.15%4,424.8+9.38514Auctions
2023-07-134,510.70+0.49%4,501.3+9.4847PPI, Claims, EIA, Auctions
2023-06-134,369.47+0.30%4,363.7+5.8907CPI, Auctions
2023-06-124,339.74+0.69%4,317.2+22.69030Auctions
2023-03-283,970.86+0.02%3,965.9+5.08021Confidence, Fed, Auctions
2023-03-214,000.74+0.23%3,986.3+14.410018Auctions
2023-02-154,146.10+0.84%4,129.5+16.79019Retail sales, VIX settlement, EIA, Auctions
2023-01-264,060.85+0.33%4,036.6+24.39010Housing, GDP, Claims, EIA, Auctions
2023-01-113,969.25+0.77%3,948.0+21.3956VIX settlement, EIA, Auctions
2022-12-123,989.64+1.11%3,959.8+29.8898Auctions
2022-11-224,005.01+0.86%3,980.3+24.71004Auctions
2022-11-103,954.42+1.62%3,911.2+43.3950CPI, Claims, EIA, Auctions
2022-09-283,719.20+1.76%3,699.3+19.98512VIX settlement, Fed, EIA, Auctions
2022-08-254,199.12+1.06%4,168.9+30.29511GDP, Claims, EIA, Auctions
2022-08-104,208.70+0.32%4,198.1+10.68514CPI, 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.