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

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

66 of 1,118 sessions match. Of them 0% closed above the flip (archive 54%) and the mean open-to-close move was 0.66% (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
2026-10-067,818.72+0.07%7,824.5-5.8309Auctions
2026-09-107,591.60-0.02%7,594.4-2.84014PPI, Claims, EIA, Auctions
2026-09-087,673.17-0.43%7,685.0-11.82021Auctions
2026-08-127,748.52-0.17%7,750.6-2.13522CPI, VIX settlement, EIA, Auctions
2026-08-117,727.62-0.45%7,735.1-7.5209Auctions
2026-07-287,428.00+0.19%7,436.5-8.53015Confidence, Auctions
2026-07-277,412.22-0.78%7,412.3-0.1405Housing, Auctions
2026-06-257,355.80-0.86%7,357.7-1.93019PCE, Housing, GDP, Claims, EIA, Auctions
2026-06-247,358.75-0.22%7,377.4-18.7458Housing, VIX settlement, EIA, Auctions, Fed
2026-06-107,267.52-1.08%7,285.6-18.1353CPI, VIX settlement, EIA, Auctions
2026-03-266,477.72-0.97%6,521.8-44.1304Claims, EIA, Auctions
2026-03-256,591.77-0.45%6,594.5-2.82531VIX settlement, EIA, Auctions
2026-03-246,556.00+0.24%6,565.0-9.03524Auctions
2026-03-176,716.85-0.28%6,719.9-3.13013Auctions
2026-03-126,673.29-0.66%6,691.9-18.63026Housing, Claims, EIA, Auctions
2026-03-106,781.42-0.20%6,805.0-23.52017Auctions
2026-02-246,890.15+0.83%6,890.8-0.6454Confidence, Auctions
2026-02-126,832.81-1.87%6,866.3-33.5351Claims, EIA, Auctions
2026-02-116,942.22-0.68%6,946.6-4.43539NFP, VIX settlement, EIA, Auctions
2026-02-106,941.12-0.44%6,957.9-16.73023Retail sales, Auctions
2026-01-276,978.77+0.21%6,982.0-3.2308Housing, Confidence, Auctions
2026-01-266,950.70+0.37%6,954.1-3.4211Housing, Auctions
2026-01-126,977.82+0.57%6,978.2-0.4371Auctions
2025-11-136,737.27-1.20%6,757.0-19.8254EIA, Auctions
2025-09-236,657.12-0.54%6,657.7-0.62517Fed, Auctions
2025-06-116,022.71-0.40%6,027.9-5.24012CPI, VIX settlement, EIA, Auctions
2025-05-085,664.05-0.13%5,692.4-28.3259Claims, EIA, Auctions
2025-04-235,377.07-0.77%5,383.2-6.1305Housing, VIX settlement, EIA, Auctions, Fed
2025-04-165,274.90-1.27%5,276.7-1.84013Retail sales, VIX settlement, EIA, Auctions, Fed
2025-03-265,712.15-1.12%5,713.5-1.3253Housing, VIX settlement, EIA, Auctions
2025-03-185,614.57-0.60%5,616.4-1.82036Housing, VIX settlement, Auctions
2025-03-135,521.45-1.11%5,537.3-15.83012PPI, Claims, EIA, Fed, Auctions
2025-03-115,572.65-0.60%5,580.3-7.74025JOLTS, Auctions
2025-02-255,955.17-0.53%5,957.5-2.32519Confidence, Auctions
2025-01-226,086.39+0.18%6,091.4-5.0261VIX settlement, Auctions
2025-01-075,908.07-1.50%5,930.9-22.8323JOLTS, Auctions
2024-12-116,083.55+0.33%6,086.7-3.1371CPI, VIX settlement, EIA, Auctions
2024-11-045,713.45-0.30%5,719.0-5.53523Housing, Auctions
2024-10-295,833.42+0.34%5,837.1-3.7208Confidence, JOLTS, Auctions
2024-08-295,592.71-0.29%5,607.0-14.3206GDP, Claims, EIA, Auctions
2024-08-285,592.71-0.59%5,592.8-0.04523VIX settlement, EIA, Auctions
2024-08-065,238.87+0.62%5,268.6-29.8358Auctions
2024-07-175,589.10-0.40%5,593.7-4.63212Housing, VIX settlement, EIA, Auctions
2024-04-175,022.95-0.98%5,032.5-9.6308VIX settlement, EIA, Auctions
2023-10-254,186.77-0.99%4,194.2-7.4256Housing, VIX settlement, EIA, Auctions
2023-10-124,349.45-0.67%4,353.0-3.64018CPI, Claims, EIA, Auctions
2023-10-104,357.87+0.41%4,363.5-5.74020Auctions
2023-09-124,462.47-0.19%4,472.4-9.94017Auctions
2023-08-234,435.60+0.75%4,436.6-1.0355Housing, VIX settlement, EIA, Auctions
2023-07-124,471.84-0.12%4,473.7-1.83715CPI, VIX settlement, EIA, Auctions
2023-06-214,365.75-0.17%4,373.1-7.43024Fed, VIX settlement, Auctions
2023-05-114,131.25+0.10%4,131.9-0.63511PPI, Claims, EIA, Auctions
2023-03-093,917.82-2.06%3,992.5-74.7457Claims, EIA, Fed, Auctions
2023-02-223,989.80-0.33%3,991.9-2.12018VIX settlement, Auctions
2023-02-094,081.49-1.74%4,099.8-18.3259Claims, EIA, Auctions, Fed
2023-02-084,119.07-0.61%4,123.6-4.63011VIX settlement, EIA, Auctions
2022-12-213,875.97+0.69%3,876.8-0.82113VIX settlement, EIA, Auctions
2022-11-213,950.72-0.15%3,952.7-1.94015Auctions
2022-11-163,960.30-0.40%3,962.9-2.63024Retail sales, VIX settlement, EIA, Auctions
2022-09-273,646.87-1.24%3,656.3-9.53510Housing, Confidence, Auctions
2022-09-203,855.72-0.28%3,856.8-1.13026Housing, Auctions
2022-08-114,205.50-0.75%4,224.9-19.4253PPI, Claims, EIA, Auctions
2022-06-273,898.57-0.70%3,904.0-5.43517Housing, Auctions
2022-06-223,760.65+1.10%3,768.4-7.7255Fed, VIX settlement, Auctions
2022-05-183,924.20-2.87%3,967.4-43.2262Housing, VIX settlement, EIA, Auctions
2022-05-113,934.19-1.40%3,992.6-58.43313CPI, 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.