MU gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Micron Technology, 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 16:00:02 ET · not updating right now
Spot
1015
from put-call parity
Zero gamma flip
973
4.1% below spot
Call wall
1020
0.5% above spot
Put wall
980
3.4% below spot
Net gamma, volume
+$875M
per 1% move
Net gamma, OI
+$374M
per 1% move
Price sits above the flip at 973: 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
1075
1070
1065
1060
1055
1050
1045
1040
1038
1035
1033
1030
1028
1025
1023
1020
call wall
1018
1015
spot
1010
1005
1000
995
990
985
980
put wall
975
970
965
960
957.5
955
By expiry, volume book
expiryflipcallputnet
2026-09-21980.71020980+$615M
2026-09-23985.91020980+$40M
2026-09-25935.11000970+$144M
2026-09-28n/a1100980+$31M
2026-10-02865.31000900+$35M
2026-10-09958.91000950+$1M
How far to trust this bookC

a single stock with an active tape; the dealer-sign convention is an approximation here.

Prints a second, regular session6.02
Strikes where the two books agree on the sign84%
Contracts traded today, expiries shown466,361

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.
  • MU 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 MU, 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 MU 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.