Delta hedging is how options dealers offset the directional risk of their books by trading the underlying — and the collective flow of that hedging is what makes dealer positioning move SPY. It’s the engine behind the whole dealer-flow framework.

What dealers are doing

Dealers (market makers) take the other side of customer options trades, which leaves them with directional (delta) risk they don’t want. To neutralize it, they buy or sell the underlying (SPY/futures) so their net delta is ~zero. As price moves, their delta changes (that’s gamma), so they must continuously re-hedge — and that constant buying and selling is a real force on price.

Why it moves the tape

The direction of hedging depends on the gamma regime: long gamma dealers hedge against the move (damping), short gamma dealers hedge with it (amplifying). Time (charm) and volatility (vanna) also change their delta, adding more hedging flows. All of it concentrates around big strikes — which is why those strikes act as levels.

Dealers don’t trade a view — they trade to stay neutral. But “staying neutral” across a giant book is itself a huge, predictable flow that bends the tape.

What it means for a scalper

Delta hedging is why dealer levels have predictive structure — price reacts at strikes because that’s where hedging concentrates. You’re trading the footprint of forced, mechanical flows, not opinions. That’s the honest edge of reading structure (still structure, not signals). See how market makers hedge for the mechanics.