0DTE Hedging Flows Are Reshaping Intraday Gamma

0DTE options now represent ~half of SPX options volume — and they've changed intraday gamma math:

• Continuous hedging cycles — dealers re-hedge intraday, not just at open/close
• Micro-squeezes — 0DTE call surges trigger real-time dealer buying, creating 15-minute acceleration episodes
• Pinning behavior — large 0DTE OI at a strike can magnetize price as dealers defend their books

The problem for GEX models: most published gamma calculations use end-of-day data — they miss the intraday flow that now dominates. Our strike heatmap is the attempt to surface the dynamic.

Watch the 0DTE flow during Micron's first hour Thursday — the real-time dealer response is the tell.