MSFT gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Microsoft, 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 45 days.

data as of 2026-09-18 16:00:03 ET · not updating right now
Spot
493.5
from put-call parity
Zero gamma flip
483.7
2.0% below spot
Call wall
495
0.3% above spot
Put wall
490
0.7% below spot
Net gamma, volume
+$224M
per 1% move
Net gamma, OI
+$366M
per 1% move
Price sits above the flip at 483.7: on this book dealer hedging leans against a move rather than adding to it.
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
530
527.5
525
522.5
520
517.5
515
512.5
510
507.5
505
502.5
500
497.5
495
call wall
492.5
spot
490
put wall
487.5
485
482.5
480
477.5
475
472.5
470
467.5
465
462.5
460
457.5
455
By expiry, volume book
expiryflipcallputnet
2026-09-21487.4495490+$92M
2026-09-23492.3495487.5+$2M
2026-09-25481502.5485+$72M
2026-09-28510.3500497.5-$2M
2026-09-30524.3487.5500-$2M
2026-10-02475.4530490+$13M
How far to trust this bookD

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

Prints a second, regular session1.45
Strikes where the two books agree on the sign96%
Contracts traded today, expiries shown176,490

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.
  • MSFT 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 MSFT, 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 MSFT 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.