OPEX Tracker — bpleone / trade

📈 OPEX week historical

SPY closes positive ~62% of OPEX weeks since 2015. Tue–Wed runs are most consistent. Mon often weak from weekend gamma decay.

⚡ Post-OPEX gap risk

Monday after OPEX has historically gapped >1% in either direction 35% of the time — much higher than non-OPEX Mondays (18%). Adjust position size.

🌀 Quarterly OPEX (Q-end)

3rd Fridays of Mar/Jun/Sep/Dec = "triple witching". Biggest gamma unwind. Volatility expansion in following week historically.

🧠 Why OPEX matters

Monthly options expire on the 3rd Friday. Massive gamma + delta positions roll off, forcing dealers to re-hedge — often producing predictable price action in the following week. Key implications:

Pre-OPEX (T-5 to T-1): Dealer gamma is largest, prices pin (mean-revert) near key strikes.
OPEX day: Pinning effect maxes. Watch for end-of-day fades into max-pain.
Post-OPEX (T+1 to T+5): Gamma unwind = expanded volatility, larger moves. Trend-following works better here.

See GEX PRO for dealer gamma snapshots + flip levels.