Should I adjust position size before GDP MoM?

Yes adjust position size before GDP MoM. High-impact economic releases like GDP often spike implied volatility and widen bid-ask spreads on SPX, which directly hurts iron condor profitability through vega and gamma risk.

Current VIX level matters most. If VIX sits above 18-20 ahead of the print, cut size by 30-50% or sit out entirely. Below 15 you can run closer to normal size but still reduce by 20% to protect against headline whipsaw.

Under ALVH methodology keep your defined-risk exposure below 1.5% of portfolio on event days. Tighten wing widths to 15-20 points instead of 25-30 to lower vega and reduce the dollar impact of any volatility expansion. This preserves the same number of contracts while cutting tail risk.

Enter or adjust the iron condor at least 30-45 minutes before the release so you capture tighter pre-event pricing. If you already have an open condor, roll the untested side or buy back the losing wing early rather than hold through the print.

Manage wing width aggressively post-event once the initial volatility crush occurs. Smaller size before GDP keeps drawdowns survivable and gives you dry powder to add after the dust settles.