DJX gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Dow Jones Industrial Average (1/100), 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 15:57:31 ET · replay DJX in the terminal
Spot
518.5
from put-call parity
Zero gamma flip
523.9
1.0% above spot
Call wall
525
1.2% above spot
Put wall
515
0.7% below spot
Net gamma, volume
-$381K
per 1% move
Net gamma, OI
+$73M
per 1% move
Price sits below the flip at 523.9: on this book dealer hedging adds to a move rather than leaning against it.
The session, 2026-10-01 priceflipcall wallput wall
510510514.6509.8 net gamma, volume book09:3010:3011:3012:3013:3014:3015:30
day10-1210-0910-0810-0710-0610-0510-0210-0109-3009-2909-2809-25 83 points · volume book · levels drawn as they stood
Strikes through the day levelchange since the open absorbs a movefeeds itprice
53553052552051551050550049549048509:3010:3011:3012:3013:3014:3015:30
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
540
535
530
525
call wall
520
spot
515
put wall
510
505
500
495
By expiry, volume book
expiryflipcallputnet
2026-10-16528.9525515-$517K
2026-11-20493.4510495+$134K
2026-12-18517.5530510+$2K
How far to trust this bookB

an index or an ETF; the convention holds, the tape is thinner.

Prints a second, regular session0
Strikes where the two books agree on the sign70%
Contracts traded today, expiries shown229

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.
  • Two roots of the index, the daily and the monthly, are added together on the dates they share.
  • Every figure is dollars of dealer delta per 1% move in DJX, 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 DJX is below its flip?

Net dealer gamma on this book is negative, so hedging flows tend to add to 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.