SNDK gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Sandisk, from the option chain itself: two books, the level where net gamma changes sign, and the two strikes that carry the most. Expiries out to 120 days.

data as of 2026-10-12 15:59:08 ET · replay SNDK in the terminal
Spot
1487
from put-call parity
Zero gamma flip
1446
2.8% below spot
Call wall
1600
7.6% above spot
Put wall
1400
5.9% below spot
Net gamma, volume
+$74M
per 1% move
Net gamma, OI
-$158M
per 1% move
Price sits above the flip at 1446: on this book dealer hedging leans against a move rather than adding to it. The two books disagree: price is above one flip and below the other, and that split is the reading.
The session, 2026-09-28 priceflipcall wallput wall
1700170016341713 net gamma, volume book09:3010:3011:3012:3013:3014:3015:30
day10-1210-0910-0810-0710-0610-0510-0210-0109-3009-2909-2809-25 82 points · volume book · levels drawn as they stood
Strikes through the day levelchange since the open absorbs a movefeeds itprice
1770176517601755175017451740173517301725172017151710170517001695169016851680167516701665166009:3010:3011:3012:3013:3014:3015:30
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
1560
1555
1550
1545
1540
1535
1530
1525
1520
1515
1510
1505
1500
1495
1490
1485
spot
1480
1475
1470
1465
1460
1455
1450
1445
1440
1435
1430
1425
1420
1415
1410
By expiry, volume book
expiryflipcallputnet
2026-10-16145616001400+$50M
2026-10-23131615001580+$24M
2026-10-30142815001450+$2M
2026-11-06157116501500-$656K
2026-11-13156516001450-$516K
2026-11-20150216001470-$324K
How far to trust this bookD

a single stock with a thin tape; read the shape, not the sign.

Prints a second, regular session2.68
Strikes where the two books agree on the sign64%
Contracts traded today, expiries shown150,833

What this page assumes

  • Calls count as dealer-long gamma and puts as dealer-short. That is a convention, not a measurement: open interest does not say who holds a contract.
  • The volume book signs today's traded contracts. The open-interest book uses positions as of the last close and does not move inside the day.
  • Spot is derived from the option quotes by put-call parity, so it can sit a few cents from the last trade in the underlying.
  • SNDK options are American style and the underlying may pay a dividend. Each expiry is priced off its own forward from put-call parity, and gamma is Black-Scholes on that forward. Deep in-the-money contracts near a dividend are the weak spot.
  • Every figure is dollars of dealer delta per 1% move in SNDK, the unit that compares across symbols.
  • There is no tape-signed book on this page. That book exists only where a live engine runs.

Questions

What does it mean that SNDK is above its flip?

Net dealer gamma on this book is positive, so hedging flows tend to lean against a move. It says nothing about direction.

Why are there two books?

Open interest is positioning as it stood at the last close. Volume is what traded today. When they disagree, that split is the reading.

Is this a trading signal?

No. We tested wall touches and flip crosses on SPX across more than a thousand sessions and found no edge that survives costs. These are measurements of where hedging concentrates.

How is this different from the SPX terminal?

SPX runs on a live engine: every second, with a third book signed print by print from the trade tape. This page is rebuilt from chain snapshots and carries the two conventional books only.