Dealer gamma · ISRG
Computed 2026-09-21 after the close from ISRG's listed option chain. Nothing here is predicted: these are the strikes where dealer hedging concentrates, recomputed every trading night.
Computed 2026-09-21 22:51 · refreshed nightly
| Night | Spot | Flip | Call wall | Put wall | Net gamma |
|---|---|---|---|---|---|
| 2026-09-21 | 393.33 | 445 | 400 | 350 | +$0.01bn |
| 2026-09-20 | 393.33 | 520 | 400 | 350 | +$0.00bn |
| 2026-09-19 | 393.33 | 520 | 400 | 350 | +$0.00bn |
| 2026-09-18 | 383.54 | 420 | 400 | 350 | +$0.01bn |
| 2026-09-17 | 382.29 | 475 | 400 | 350 | +$0.01bn |
| 2026-09-16 | 382.29 | 520 | 400 | 350 | +$0.01bn |
| 2026-09-15 | 377.94 | — | 400 | 350 | -$0.00bn |
| 2026-09-14 | 369.15 | — | 400 | 350 | -$0.00bn |
What a wall is: the strike where dealers' hedging exposure concentrates. Price approaching a large call wall tends to meet hedging flow that leans against the move; losing a put wall can accelerate one. A wall is a level that usually matters — not a promise. Our index levels are graded publicly against every session for exactly that reason.
Where this data goes: this same nightly computation feeds the Intel Clearance morning wire — filings, 13F moves, dark-pool share and these walls on the names you follow, read for you by 07:40. And inside the terminal, the index books recompute through the session as 0DTE flow rebuilds the surface.
