How does SPX trade when net dealer gamma sits at the 80th percentile or above?

SPX sessions with the net-gamma percentile 80 and above · 783 sessions · the archive filtered by the dealer book · all sessions · the calendar

Short answer. 783 of 1,103 archived SPX sessions matched. Of them 96% closed above the zero-gamma flip (archive 84%), 72% held the expected-hold band (archive 60%) and the mean open-to-close move was 0.53% (archive 0.60%). Counts over finished sessions, recomputed as the archive grows; a share equal to the archive's is a base rate, not a pattern.

783 of 1,103 sessions match. Of them 96% closed above the flip (archive 84%), 72% held the expected-hold band (archive 60%), mean open-to-close move 0.53% (archive 0.60%).

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, whether the expected-hold band held, 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 flipPctlCrossBandEvents
2026-09-157,585.17-0.33%7,664.3-79.11001heldAuctions
2026-09-147,620.30+0.26%7,665.1-44.8882broke
2026-09-097,636.30-0.22%7,692.7-56.4822heldVIX settlement, Auctions
2026-09-047,718.57-0.24%7,641.2+77.4950brokeNFP
2026-09-037,747.67+0.62%7,659.6+88.11001brokeClaims, ISM, EIA, Auctions
2026-08-267,675.95+0.13%7,663.1+12.8993brokePCE, Housing, GDP, VIX settlement, EIA, Auctions
2026-08-257,677.30-0.05%7,621.5+55.8980heldHousing, Confidence, Auctions
2026-08-247,653.24-0.03%7,604.6+48.6821held
2026-08-217,673.55+0.02%7,614.1+59.4990heldOpex
2026-08-207,640.30-0.50%7,632.7+7.61000heldClaims, EIA, Auctions
2026-08-197,706.75-0.22%7,676.0+30.8960heldVIX settlement, EIA, Auctions
2026-08-147,785.87-0.20%7,751.6+34.31000heldRetail sales, UMich
2026-08-137,798.82+0.41%7,723.2+75.61000heldPPI, Claims, EIA, Auctions
2026-08-127,748.52-0.17%7,667.0+81.51000heldCPI, VIX settlement, EIA, Auctions
2026-08-117,727.62-0.45%7,698.5+29.1880heldAuctions
2026-08-107,752.95-0.04%7,700.5+52.41000held
2026-08-077,758.52+0.33%7,679.1+79.4830heldNFP
2026-08-067,709.60-0.21%7,652.5+57.1970heldClaims, EIA
2026-08-037,600.47+1.06%7,452.4+148.11002brokeISM, Housing, Fed, Refunding
2026-07-307,437.15+0.79%7,407.7+29.41003brokePCE, GDP, Claims, EIA
2026-07-277,412.22-0.78%7,363.7+48.51000heldHousing, Auctions
2026-07-247,410.80-0.01%7,361.6+49.2988heldHousing
2026-07-227,499.47+0.08%7,440.9+58.61000heldVIX settlement, EIA, Auctions
2026-07-217,509.67+0.37%7,492.2+17.51000broke
2026-07-167,533.67-0.32%7,479.8+53.9982heldRetail sales, Claims, EIA
2026-07-137,515.25-0.56%7,493.8+21.41000held
2026-07-107,575.01+0.33%7,483.8+91.21000held
2026-07-097,542.75+0.69%7,536.1+6.61000brokeClaims, EIA, Auctions
2026-07-087,482.92+0.34%7,370.7+112.2940heldVIX settlement, EIA, Auctions
2026-07-077,503.17-0.39%7,432.2+71.0990heldAuctions
2026-07-067,537.25+0.25%7,428.7+108.61000heldISM
2026-07-027,479.37-0.35%7,406.2+73.2950heldNFP, Housing, Claims, EIA
2026-06-307,498.14+0.77%7,488.9+9.2940brokeConfidence, JOLTS
2026-06-297,440.62+0.69%7,303.4+137.2990held
2026-06-267,339.17+0.36%7,202.7+136.5814brokeUMich, Opex
2026-06-257,355.80-0.86%7,293.6+62.2940heldPCE, Housing, GDP, Claims, EIA, Auctions
2026-06-247,358.75-0.22%7,293.2+65.6960brokeHousing, VIX settlement, EIA, Auctions, Fed
2026-06-237,365.75+0.13%7,297.0+68.8982heldAuctions
2026-06-227,474.86-0.58%7,385.7+89.21000held
2026-06-187,499.42-0.09%7,488.4+11.01002brokeClaims, EIA, Opex
2026-06-177,420.70-1.31%7,397.2+23.5932brokeRetail sales, VIX settlement, EIA, FOMC
2026-06-167,511.70-0.61%7,526.0-14.3815brokeHousing, Auctions
2026-06-127,431.79+0.32%7,392.4+39.4982heldUMich
2026-06-117,393.92+1.35%7,306.3+87.6912brokePPI, Claims, EIA, Fed, Auctions
2026-06-087,405.60-0.67%7,389.7+15.9940held
2026-06-047,585.25+0.68%7,476.7+108.61001heldClaims, Fed, EIA
2026-06-037,554.39-0.60%7,542.6+11.8970heldHousing, ISM, EIA, Fed
2026-06-027,611.15+0.31%7,526.5+84.61000heldVIX settlement, JOLTS
2026-06-017,599.70+0.45%7,506.9+92.81000heldISM, Housing
2026-05-287,563.45+0.59%7,455.3+108.11000heldPCE, Housing, GDP, Claims, EIA, Auctions
2026-05-277,520.30-0.09%7,445.0+75.31000heldVIX settlement, Auctions
2026-05-267,519.02+0.03%7,461.9+57.11001heldConfidence, Auctions
2026-05-227,473.35-0.15%7,413.2+60.2956brokeUMich
2026-05-217,445.56+0.62%7,293.8+151.81000heldHousing, Claims, EIA
2026-05-207,432.50+0.79%7,284.4+148.1950heldEIA, Auctions
2026-05-197,354.17-0.17%7,256.5+97.71000heldVIX settlement
2026-05-157,407.72-0.30%7,328.6+79.1981heldOpex
2026-05-147,501.21+0.51%7,491.8+9.41007brokeRetail sales, Claims, EIA
2026-05-137,444.67+0.61%7,319.6+125.11000heldPPI, VIX settlement, EIA, Auctions
2026-05-127,400.75+0.18%7,396.0+4.8848brokeCPI, Auctions
2026-05-117,412.04+0.29%7,378.8+33.2900heldAuctions
2026-05-087,398.37+0.37%7,382.7+15.7990brokeNFP, UMich
2026-05-077,336.90-0.48%7,303.3+33.61000heldClaims, Housing, EIA
2026-05-057,259.52+0.26%7,247.3+12.210012brokeHousing, ISM, JOLTS
2026-05-047,200.92-0.26%7,195.2+5.710018brokeHousing, Fed
2026-05-017,229.45-0.07%7,226.3+3.1990heldISM
2026-04-307,209.79+0.69%7,059.0+150.8982heldPCE, GDP, Claims, EIA
2026-04-297,136.05+0.11%7,120.2+15.91004brokeHousing, Refunding, VIX settlement, EIA, FOMC
2026-04-287,138.45+0.07%7,063.2+75.31000heldConfidence, Auctions
2026-04-277,173.80+0.27%7,122.9+50.9870heldAuctions, Refunding
2026-04-247,164.55+0.53%7,055.7+108.91001heldUMich
2026-04-217,063.60-0.78%7,059.6+4.01002brokeRetail sales
2026-04-207,109.05-0.06%7,048.6+60.41000held
2026-04-177,125.72+0.57%7,076.4+49.31000heldOpex
2026-04-167,041.02+0.13%6,971.5+69.51000heldClaims, EIA
2026-04-146,966.67+0.92%6,920.5+46.2990brokePPI
2026-04-136,886.26+1.28%6,891.2-4.9816broke
2026-04-106,816.69-0.31%6,769.2+47.5980heldCPI, Housing, UMich
2026-04-096,825.15+0.81%6,700.7+124.41000heldPCE, GDP, Claims, EIA, Auctions
2026-04-086,782.20-0.06%6,772.4+9.8976brokeVIX settlement, EIA, Auctions
2026-04-066,611.25+0.33%6,572.9+38.41000heldISM
2026-04-026,582.42+1.39%6,525.0+57.41002brokeClaims, EIA
2026-04-016,574.47+0.13%6,505.1+69.4980heldRetail sales, VIX settlement, ISM, EIA
2026-03-306,344.00-1.19%6,284.2+59.8990heldFed
2026-03-276,369.70-1.16%6,306.9+62.81000brokeUMich
2026-03-266,477.72-0.97%6,458.4+19.31000heldClaims, EIA, Auctions
2026-03-256,591.77-0.45%6,531.5+60.3990heldVIX settlement, EIA, Auctions
2026-03-246,556.00+0.24%6,473.4+82.6980heldAuctions
2026-03-236,582.06-0.30%6,487.0+95.1960heldHousing
2026-03-206,506.42-1.18%6,429.4+77.0970brokeOpex
2026-03-196,606.92+0.61%6,495.7+111.2980heldHousing, Claims, EIA, Fed
2026-03-186,624.85-0.98%6,572.1+52.8968brokeHousing, PPI, VIX settlement, EIA, FOMC
2026-03-176,716.85-0.28%6,685.7+31.2970heldAuctions
2026-03-166,699.55+0.12%6,583.5+116.1941held
2026-03-136,631.49-1.18%6,574.8+56.7960heldPCE, Housing, GDP, JOLTS, UMich
2026-03-126,673.29-0.66%6,607.4+65.91004heldHousing, Claims, EIA, Auctions
2026-03-116,775.15-0.24%6,671.9+103.31000heldCPI, VIX settlement, EIA, Auctions
2026-03-106,781.42-0.20%6,716.5+64.9970heldAuctions
2026-03-066,739.82-0.02%6,728.2+11.61000brokeNFP, Retail sales
2026-03-056,830.87-0.12%6,709.2+121.71000brokeClaims, EIA
2026-03-046,870.30+0.40%6,724.9+145.4980heldISM, EIA, Fed
2026-03-036,816.60+0.60%6,686.0+130.6930heldVIX settlement
2026-03-026,881.05+1.10%6,759.9+121.2950heldISM
2026-02-276,879.27+0.43%6,745.2+134.1950heldPPI, Housing, Opex
2026-02-266,908.31-0.45%6,791.1+117.2960heldClaims, Fed, EIA, Auctions
2026-02-256,946.55+0.31%6,849.9+96.71000heldVIX settlement, EIA, Auctions
2026-02-246,890.15+0.83%6,770.7+119.41000heldConfidence, Auctions
2026-02-206,909.09+1.06%6,805.7+103.41001heldPCE, GDP, UMich, Housing, Opex
2026-02-196,861.35+0.04%6,756.5+104.9980heldClaims, EIA
2026-02-186,880.55+0.46%6,795.1+85.4910heldHousing, VIX settlement, Auctions
2026-02-176,843.76+0.29%6,724.6+119.2930held
2026-02-126,832.81-1.87%6,782.2+50.6980heldClaims, EIA, Auctions
2026-02-116,942.22-0.68%6,874.8+67.4990heldNFP, VIX settlement, EIA, Auctions
2026-02-106,941.12-0.44%6,895.2+45.9970heldRetail sales, Auctions
2026-02-096,964.56+0.81%6,869.3+95.3990held
2026-02-066,931.92+1.36%6,786.0+145.9992brokeUMich
2026-02-056,799.37-0.34%6,747.3+52.11000heldClaims, JOLTS, EIA
2026-02-046,882.81-0.55%6,777.5+105.3850brokeRefunding, VIX settlement, ISM, EIA, Fed
2026-02-036,917.89-1.02%6,828.9+89.0920held
2026-02-026,976.55+0.71%6,876.3+100.31000heldISM, Fed, Refunding
2026-01-306,938.85-0.19%6,845.5+93.4891heldPPI
2026-01-296,967.37-0.31%6,814.6+152.8850brokeHousing, Claims, EIA, Auctions
2026-01-266,950.70+0.37%6,881.4+69.3991heldHousing, Auctions
2026-01-236,915.51+0.13%6,878.3+37.2980heldUMich
2026-01-216,875.10+0.73%6,858.4+16.71007brokeVIX settlement, Housing, Auctions
2026-01-206,796.40-0.75%6,737.2+59.2930held
2026-01-166,939.67-0.33%6,900.2+39.51000heldOpex
2026-01-156,944.02-0.30%6,904.8+39.2923heldClaims, EIA
2026-01-136,963.52-0.27%6,920.0+43.5970heldCPI, Housing, Auctions
2026-01-126,977.82+0.57%6,911.4+66.4991heldAuctions
2026-01-096,966.60+0.49%6,899.1+67.5962heldNFP, Housing, UMich, Fed
2026-01-086,921.92+0.13%6,876.2+45.7970heldClaims, EIA
2026-01-076,921.37-0.33%6,903.3+18.1931heldHousing, VIX settlement, JOLTS, EIA
2026-01-066,944.74+0.52%6,879.5+65.21000heldISM
2026-01-056,901.52+0.05%6,829.4+72.1980held
2026-01-026,858.32-0.40%6,786.7+71.6961heldISM, EIA
2025-12-316,846.45-0.78%6,840.8+5.6950heldClaims, VIX settlement, EIA
2025-12-306,895.89-0.13%6,878.5+17.4990heldConfidence
2025-12-296,905.56+0.02%6,856.3+49.31001held
2025-12-266,929.70-0.03%6,888.1+41.61000heldUMich, EIA
2025-12-246,932.00+0.35%6,922.0+10.01000brokeClaims, VIX settlement, EIA, Auctions
2025-12-236,909.75+0.42%6,839.1+70.61000heldPCE, Housing, GDP, Auctions
2025-12-226,878.40+0.18%6,821.4+57.01001heldAuctions
2025-12-196,834.47+0.50%6,768.0+66.51000heldOpex
2025-12-186,775.22-0.21%6,722.7+52.5900heldCPI, Claims, EIA
2025-12-176,722.06-1.21%6,697.9+24.21001heldVIX settlement, EIA, Auctions
2025-12-156,816.60-0.65%6,756.0+60.61000held
2025-12-126,827.49-0.91%6,754.7+72.81000heldUMich
2025-12-116,900.94+0.63%6,811.1+89.81001heldClaims, EIA, Auctions
2025-12-106,886.21+0.73%6,827.2+59.0961brokeVIX settlement, EIA, FOMC
2025-12-096,840.40-0.07%6,803.4+37.01000heldJOLTS, Auctions
2025-12-086,846.39-0.42%6,802.9+43.51000heldAuctions
2025-12-056,870.36-0.03%6,806.9+63.51001heldPCE
2025-12-046,855.99-0.10%6,816.6+39.4940heldHousing, Claims, EIA
2025-12-036,850.34+0.49%6,758.0+92.31000heldVIX settlement, ISM, EIA
2025-12-026,829.84-0.01%6,770.3+59.51000heldFed
2025-11-286,848.69+0.04%6,785.7+63.0992heldUMich, EIA, Opex
2025-11-266,812.45+0.26%6,769.8+42.61000heldHousing, Claims, VIX settlement, EIA, Auctions, Fed
2025-11-246,705.67+0.92%6,529.6+176.1950heldAuctions
2025-11-216,602.80+0.46%6,522.7+80.1930brokeFed, Opex
2025-11-206,539.17-3.04%6,518.4+20.89612brokeNFP, Claims, EIA
2025-11-196,642.05+0.31%6,542.4+99.7960heldVIX settlement, EIA, Auctions
2025-11-186,617.56-0.33%6,544.1+73.5880heldHousing
2025-11-176,672.66-0.52%6,603.1+69.6870brokeHousing
2025-11-136,737.27-1.20%6,690.3+47.0901heldEIA, Auctions
2025-11-116,846.06+0.32%6,758.8+87.3960held
2025-11-106,832.77+0.54%6,738.3+94.5944heldAuctions
2025-11-076,728.72+0.64%6,599.3+129.4935held
2025-11-046,771.87-0.17%6,731.8+40.1900held
2025-11-036,851.32-0.32%6,771.9+79.4971heldISM, Fed, Refunding
2025-10-306,823.12-0.47%6,796.9+26.2880heldEIA
2025-10-286,891.30+0.03%6,861.5+29.8900heldConfidence, Auctions
2025-10-236,738.30+0.51%6,670.0+68.3990heldEIA
2025-10-226,699.45-0.50%6,611.6+87.81000heldVIX settlement, EIA, Auctions
2025-10-216,735.02+0.00%6,675.3+59.7840held
2025-10-206,735.32+0.47%6,649.2+86.11000held
2025-10-176,663.37+0.78%6,537.9+125.5950heldOpex
2025-10-146,645.20+0.83%6,537.0+108.21000heldFed
2025-10-136,654.67+0.38%6,580.9+73.81000held
2025-10-096,734.67-0.35%6,675.9+58.81000heldFed, EIA, Auctions
2025-10-086,754.17+0.45%6,652.1+102.11000heldVIX settlement, EIA, Auctions
2025-10-076,714.25-0.49%6,674.5+39.81000heldAuctions
2025-10-066,740.57+0.06%6,682.5+58.11000held
2025-10-036,716.00-0.16%6,699.2+16.81000heldISM
2025-10-026,715.97-0.12%6,641.0+75.0991heldEIA
2025-10-016,711.67+0.81%6,623.1+88.61000heldVIX settlement, ISM, EIA
2025-09-306,688.27+0.50%6,554.9+133.4970heldConfidence, JOLTS
2025-09-296,661.52-0.09%6,628.5+33.0971held
2025-09-266,643.40+0.41%6,552.0+91.4970heldPCE, UMich
2025-09-256,604.25+0.08%6,528.2+76.11000heldHousing, GDP, Claims, EIA, Auctions
2025-09-246,637.55-0.44%6,575.2+62.4880heldHousing, VIX settlement, EIA, Auctions
2025-09-226,694.80+0.68%6,627.5+67.3994held
2025-09-196,664.50+0.30%6,594.4+70.11000heldOpex
2025-09-186,631.82+0.15%6,598.3+33.5860heldClaims, EIA
2025-09-176,600.65-0.18%6,466.4+134.3840heldHousing, VIX settlement, EIA, FOMC
2025-09-126,584.85+0.00%6,548.9+36.01000heldUMich
2025-09-096,513.07+0.23%6,428.9+84.2990heldAuctions
2025-09-086,495.60+0.05%6,455.8+39.81000held
2025-09-056,481.37-0.69%6,390.5+90.9980heldNFP
2025-09-026,415.17+0.60%6,307.1+108.11000heldISM, Housing

Showing the first 200 of 783; 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.