XLK gamma exposure: flip, call wall, put wall

Dealer gamma by strike for Technology Select Sector SPDR, 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 2026-11-02 16:15:00 ET · not updating right now · replay XLK in the terminal
Spot
174.8
from put-call parity
Zero gamma flip
n/a
outside the range
Call wall
185
5.8% above spot
Put wall
180
3.0% above spot
Net gamma, volume
-$11M
per 1% move
Net gamma, OI
-$50M
per 1% move
No zero-gamma level inside the searched range: net gamma stays negative across it.
The session, 2026-10-26 priceflipcall wallput wall
190181182.4186.3 net gamma, volume book09:3010:3011:3012:3013:3014:3015:30
day11-0210-3010-2910-2810-2710-2610-2310-2210-2110-2010-1910-16 82 points · volume book · levels drawn as they stood
Strikes through the day levelchange since the open absorbs a movefeeds itprice
195194193192.5192191190189188187.5187186185184183182.5182181180179178177.517709:3010:3011:3012:3013:3014:3015:30
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
187.5
187
186
185
call wall
184
183
182.5
182
181
180
put wall
179
178
177.5
177
176
175
spot
174
173
172.5
172
171
170
169
168
167.5
167
166
165
164
163
162.5
By expiry, volume book
expiryflipcallputnet
2026-11-06173.7184165+$180K
2026-11-13n/a185170-$818K
2026-11-20n/a182.5180-$8M
2026-11-27n/a172.5179-$49K
2026-12-04n/a178170-$461K
2026-12-11173.8179187.5+$2K
How far to trust this bookB

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

Prints a second, regular session0.27
Strikes where the two books agree on the sign76%
Contracts traded today, expiries shown32,139

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.
  • XLK 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 XLK, 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 XLK 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.