How does SPX trade on days it closes in negative gamma?

SPX sessions closed in negative gamma · 499 sessions · the archive filtered by the dealer book · all sessions · the calendar

Short answer. 499 of 1,121 archived SPX sessions matched. Of them the mean open-to-close move was 0.63% (archive 0.59%). Counts over finished sessions, recomputed as the archive grows; a share equal to the archive's is a base rate, not a pattern.

499 of 1,121 sessions match. Of them 0% closed above the flip (archive 55%) 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
2026-10-087,764.20-0.12%7,765.0-0.821Claims, EIA, Auctions
2026-10-067,819.31+0.08%7,825.7-6.47Auctions
2026-10-027,722.25-0.10%7,722.3-0.17015NFP, Housing
2026-09-307,651.51-0.55%7,700.1-48.6455PCE, GDP, Fed, VIX settlement, EIA
2026-09-287,683.49-0.30%7,693.7-10.22514Retail sales
2026-09-237,705.12-0.65%7,716.5-11.302VIX settlement, EIA, Auctions
2026-09-227,764.70-0.10%7,765.4-0.71023Auctions
2026-09-167,551.90-0.71%7,580.0-28.17013Retail sales, VIX settlement, EIA, FOMC
2026-09-157,584.55-0.34%7,586.0-1.4805Auctions
2026-09-147,620.56+0.27%7,626.6-6.1356
2026-09-117,657.27-0.02%7,666.6-9.31013CPI, UMich, Fed
2026-09-107,591.60-0.02%7,597.6-6.04014PPI, Claims, EIA, Auctions
2026-09-097,636.50-0.22%7,643.7-7.27033VIX settlement, Auctions
2026-09-087,673.17-0.43%7,687.6-14.42021Auctions
2026-09-017,630.64-0.01%7,639.0-8.3108ISM, JOLTS, Housing
2026-08-287,711.50-0.34%7,720.5-9.0209UMich
2026-08-247,653.24-0.03%7,657.1-3.84512
2026-08-217,673.55+0.02%7,676.7-3.15034Opex
2026-08-207,640.30-0.50%7,668.5-28.2029Claims, EIA, Auctions
2026-08-197,706.75-0.22%7,718.9-12.21522VIX settlement, EIA, Auctions
2026-08-187,690.64-0.22%7,703.7-13.11530Housing, Auctions
2026-08-177,745.45-0.53%7,767.5-22.1010
2026-08-127,748.52-0.17%7,750.6-2.03522CPI, VIX settlement, EIA, Auctions
2026-08-117,727.62-0.45%7,736.1-8.4209Auctions
2026-08-107,752.95-0.04%7,754.9-1.93013
2026-08-067,709.60-0.21%7,715.7-6.15028Claims, EIA
2026-08-057,712.99-0.94%7,743.6-30.6151Refunding, VIX settlement, ISM, EIA
2026-07-297,317.75-1.35%7,389.8-72.01515VIX settlement, EIA, FOMC
2026-07-287,428.00+0.19%7,432.2-4.23015Confidence, Auctions
2026-07-247,410.80-0.01%7,422.2-11.45012Housing
2026-07-227,499.47+0.08%7,507.7-8.2521VIX settlement, EIA, Auctions
2026-07-207,443.21-0.78%7,469.8-26.61513
2026-07-177,458.16+0.12%7,471.9-13.82510Housing, UMich, Opex
2026-07-167,533.67-0.32%7,542.1-8.4357Retail sales, Claims, EIA
2026-07-137,515.25-0.56%7,529.5-14.3021
2026-07-077,503.17-0.39%7,504.8-1.75512Auctions
2026-07-017,483.35+0.14%7,497.6-14.23015VIX settlement, ISM, Housing, EIA
2026-06-267,339.17+0.36%7,361.2-22.01020UMich, Opex
2026-06-257,355.80-0.86%7,365.2-9.43019PCE, Housing, GDP, Claims, EIA, Auctions
2026-06-247,358.75-0.22%7,374.9-16.2458Housing, VIX settlement, EIA, Auctions, Fed
2026-06-237,365.75+0.13%7,388.9-23.154Auctions
2026-06-227,474.86-0.58%7,475.9-1.08510
2026-06-177,420.70-1.31%7,478.2-57.4359Retail sales, VIX settlement, EIA, FOMC
2026-06-167,511.70-0.61%7,535.5-23.855Housing, Auctions
2026-06-157,553.95+0.24%7,558.2-4.2303
2026-06-107,267.52-1.08%7,317.1-49.6353CPI, VIX settlement, EIA, Auctions
2026-06-087,405.60-0.67%7,431.9-26.3017
2026-06-057,384.59-1.98%7,465.8-81.2152NFP
2026-06-037,554.39-0.60%7,569.5-15.11017Housing, ISM, EIA, Fed
2026-05-227,473.35-0.15%7,483.6-10.3255UMich
2026-05-197,354.17-0.17%7,364.8-10.72022VIX settlement
2026-05-157,407.72-0.30%7,429.9-22.12016Opex
2026-05-077,336.90-0.48%7,345.5-8.6155Claims, Housing, EIA
2026-05-047,200.92-0.26%7,205.3-4.454Housing, Fed
2026-05-017,229.45-0.07%7,246.5-17.009ISM
2026-04-237,108.32-0.16%7,113.8-5.5356Claims, EIA
2026-04-217,063.60-0.78%7,091.0-27.4511Retail sales
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
2026-03-276,369.70-1.16%6,409.8-40.108UMich
2026-03-266,477.72-0.97%6,521.3-43.6304Claims, EIA, Auctions
2026-03-256,591.77-0.45%6,598.7-6.92531VIX settlement, EIA, Auctions
2026-03-246,556.00+0.24%6,567.2-11.23524Auctions
2026-03-236,582.06-0.30%6,606.4-24.4459Housing
2026-03-206,506.42-1.18%6,534.8-28.43518Opex
2026-03-186,624.85-0.98%6,661.4-36.51010Housing, PPI, VIX settlement, EIA, FOMC
2026-03-176,716.85-0.28%6,724.8-8.03013Auctions
2026-03-166,699.55+0.12%6,700.8-1.33021
2026-03-136,631.49-1.18%6,654.4-22.9153PCE, Housing, GDP, JOLTS, UMich
2026-03-126,673.29-0.66%6,694.2-20.93026Housing, Claims, EIA, Auctions
2026-03-106,781.42-0.20%6,804.9-23.52017Auctions
2026-03-066,739.82-0.02%6,752.2-12.4518NFP, Retail sales
2026-03-046,870.30+0.40%6,874.3-4.0011ISM, EIA, Fed
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
2026-02-136,836.35+0.01%6,852.3-15.94018CPI
2026-02-126,832.81-1.87%6,874.9-42.1351Claims, EIA, Auctions
2026-02-116,942.22-0.68%6,949.1-6.83539NFP, VIX settlement, EIA, Auctions
2026-02-106,941.12-0.44%6,962.3-21.23023Retail sales, Auctions
2026-02-096,964.56+0.81%6,965.0-0.4305
2026-02-056,799.37-0.34%6,813.2-13.83014Claims, JOLTS, EIA
2026-02-046,882.81-0.55%6,888.1-5.24523Refunding, VIX settlement, ISM, EIA, Fed
2026-02-036,917.89-1.02%6,924.3-6.4608
2026-02-026,976.55+0.71%6,979.1-2.5405ISM, Fed, Refunding
2026-01-286,977.09-0.29%6,979.2-2.1658VIX settlement, EIA, FOMC
2026-01-276,978.77+0.21%6,979.9-1.1308Housing, Confidence, Auctions
2026-01-266,950.70+0.37%6,956.9-6.2211Housing, Auctions
2026-01-236,915.51+0.13%6,916.0-0.53225UMich
2026-01-226,912.90-0.12%6,918.1-5.2329PCE, GDP, Claims, EIA
2026-01-206,796.40-0.75%6,827.6-31.21611
2026-01-166,939.67-0.33%6,948.7-9.0025Opex
2026-01-156,944.02-0.30%6,959.1-15.12625Claims, EIA
2026-01-076,921.37-0.33%6,944.7-23.33711Housing, VIX settlement, JOLTS, EIA
2026-01-056,901.52+0.05%6,907.8-6.2267
2025-12-316,846.45-0.78%6,876.7-30.257Claims, VIX settlement, EIA
2025-12-306,895.89-0.13%6,902.7-6.81122Confidence
2025-12-186,775.22-0.21%6,786.9-11.61125CPI, Claims, EIA
2025-12-176,722.06-1.21%6,750.0-27.91112VIX settlement, EIA, Auctions
2025-12-156,816.60-0.65%6,821.4-4.86313
2025-12-126,827.49-0.91%6,837.8-10.3323UMich
2025-12-096,840.40-0.07%6,850.4-10.0015JOLTS, Auctions
2025-12-056,870.36-0.03%6,871.3-0.94729PCE
2025-12-016,812.80+0.09%6,823.4-10.6510ISM, Fed
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
2025-11-206,539.17-3.04%6,609.1-69.9151NFP, Claims, EIA
2025-11-186,617.56-0.33%6,637.1-19.64520Housing
2025-11-176,672.66-0.52%6,698.4-25.74014Housing
2025-11-146,733.27+0.99%6,746.0-12.73014UMich
2025-11-136,737.27-1.20%6,768.1-30.8254EIA, Auctions
2025-11-066,719.47-0.98%6,745.4-25.9012EIA
2025-11-056,796.75+0.35%6,812.5-15.8252Refunding, VIX settlement, ISM, EIA
2025-11-046,771.87-0.17%6,786.8-14.9510
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
2025-10-306,823.12-0.47%6,854.3-31.21524EIA
2025-10-246,791.30+0.16%6,798.8-7.5251CPI, UMich
2025-10-216,735.02+0.00%6,740.2-5.23021
2025-10-166,629.25-0.95%6,649.4-20.1205EIA
2025-10-156,670.77-0.21%6,673.6-2.8309VIX settlement, Fed
2025-10-106,552.80-2.81%6,626.0-73.1151UMich
2025-10-076,714.25-0.49%6,714.3-0.1159Auctions
2025-10-036,716.00-0.16%6,728.0-12.055ISM
2025-09-236,657.12-0.54%6,672.5-15.32517Fed, Auctions
2025-09-186,631.82+0.15%6,635.4-3.52522Claims, EIA
2025-09-166,607.10-0.26%6,608.4-1.31511Retail sales, Auctions
2025-09-126,584.85+0.00%6,587.5-2.7523UMich
2025-09-106,532.62-0.07%6,534.1-1.42012PPI, VIX settlement, EIA, Auctions
2025-08-256,439.75-0.23%6,456.1-16.4109Housing
2025-08-216,369.95+0.05%6,371.7-1.83038Claims, EIA
2025-08-196,411.52-0.53%6,418.8-7.3307Housing
2025-08-156,450.35-0.30%6,455.7-5.4025Retail sales, Opex
2025-08-116,373.37-0.28%6,386.5-13.13023
2025-08-056,299.50-0.51%6,309.3-9.808ISM, Auctions
2025-08-016,238.35-0.55%6,241.8-3.53711NFP, ISM, Housing
2025-07-316,341.46-1.01%6,385.0-43.5012PCE, Claims, EIA
2025-07-306,362.67-0.20%6,368.9-6.22112GDP, Refunding, VIX settlement, EIA, FOMC
2025-07-296,371.25-0.54%6,380.0-8.7169Confidence, JOLTS, Auctions
2025-07-246,363.65-0.07%6,370.7-7.01117Housing, Claims, EIA
2025-07-216,305.80-0.06%6,322.5-16.701
2025-07-156,244.07-0.85%6,261.2-17.2518CPI
2025-07-116,259.27+0.10%6,260.3-1.13714UMich
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
2025-06-185,980.50-0.10%5,995.9-15.4017Housing, Claims, VIX settlement, EIA, FOMC
2025-06-175,982.67-0.48%6,003.0-20.4359Retail sales
2025-06-166,032.42+0.28%6,032.6-0.25514Auctions
2025-06-135,976.75-0.39%5,993.7-17.02017UMich, Fed
2025-06-116,022.71-0.40%6,035.1-12.44012CPI, VIX settlement, EIA, Auctions
2025-06-096,006.00+0.01%6,010.0-4.0157
2025-06-055,940.05-0.79%5,965.2-25.11511Claims, EIA
2025-06-045,971.50-0.16%5,980.2-8.74021ISM, EIA, Fed
2025-05-285,889.85-0.66%5,909.8-20.0523VIX settlement, Auctions
2025-05-235,802.87+0.50%5,809.9-7.03514Housing, UMich
2025-05-225,841.35+0.03%5,855.2-13.91025Claims, EIA
2025-05-215,845.42-0.99%5,894.9-49.557VIX settlement, EIA, Auctions
2025-05-135,886.65+0.71%5,890.1-3.4251CPI
2025-05-095,660.15-0.46%5,662.5-2.46532UMich
2025-05-085,664.05-0.13%5,690.0-25.9259Claims, EIA, Auctions
2025-05-065,607.32+0.15%5,618.0-10.71016Auctions
2025-05-055,650.12+0.10%5,665.9-15.807ISM, Auctions
2025-05-015,602.91-0.30%5,626.7-23.8015Claims, ISM, Housing, EIA
2025-04-235,377.07-0.77%5,390.9-13.8305Housing, VIX settlement, EIA, Auctions, Fed
2025-04-175,282.85-0.33%5,299.9-17.04025Housing, Claims, EIA, Fed, Opex
2025-04-165,274.90-1.27%5,286.8-11.94013Retail sales, VIX settlement, EIA, Auctions, Fed
2025-04-155,396.91-0.33%5,407.1-10.12019
2025-04-145,405.10-0.87%5,418.6-13.42011
2025-04-084,987.15-4.77%5,082.6-95.5503Auctions
2025-04-045,074.67-3.70%5,158.6-83.9100NFP, Fed
2025-03-285,579.60-1.72%5,600.0-20.402PCE, UMich
2025-03-275,692.62-0.05%5,707.0-14.4024GDP, Claims, EIA, Auctions
2025-03-265,712.15-1.12%5,733.0-20.8253Housing, VIX settlement, EIA, Auctions
2025-03-205,662.02+0.48%5,668.6-6.6508Claims, EIA
2025-03-185,614.57-0.60%5,616.3-1.72036Housing, VIX settlement, Auctions
2025-03-135,521.45-1.11%5,542.5-21.03012PPI, Claims, EIA, Fed, Auctions
2025-03-125,600.19-0.49%5,603.1-2.95021CPI, VIX settlement, EIA, Auctions
2025-03-115,572.65-0.60%5,586.1-13.54025JOLTS, Auctions
2025-03-105,614.39-1.34%5,629.6-15.2402
2025-03-065,737.42-0.50%5,750.9-13.5406Claims, EIA
2025-03-045,778.45-0.48%5,797.6-19.23516
2025-03-035,849.17-2.04%5,908.7-59.52025ISM, Housing
2025-02-275,862.32-2.05%5,930.5-68.23023Housing, GDP, Claims, EIA
2025-02-265,956.42-0.15%5,969.4-13.0405Housing, VIX settlement, EIA, Auctions
2025-02-255,955.17-0.53%5,956.1-0.92519Confidence, Auctions
2025-02-245,984.55-0.84%6,014.4-29.809Auctions
2025-02-216,013.52-1.60%6,059.4-45.806Opex
2025-02-146,114.37-0.07%6,115.6-1.3513Retail sales, UMich
2025-02-076,026.10-1.02%6,039.8-13.7013NFP
2025-01-316,040.37-0.91%6,079.5-39.151PCE
2025-01-296,038.10-0.31%6,040.5-2.44527VIX settlement, EIA, FOMC
2025-01-246,101.27-0.30%6,105.5-4.2267UMich
2025-01-226,086.39+0.18%6,089.9-3.5261VIX settlement, Auctions
2025-01-175,996.74+0.17%5,998.4-1.6113Housing, Opex
2025-01-165,938.27-0.33%5,946.5-8.21639Retail sales, Claims, EIA
2025-01-105,826.27-0.78%5,838.5-12.34214NFP, UMich, EIA
2025-01-075,908.07-1.50%5,937.6-29.6323JOLTS, 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

Showing the first 200 of 499; the JSON carries all of them.

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.