FSLR gamma exposure: flip, call wall, put wall

Dealer gamma by strike for First Solar, 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 2026-09-25 11:43:44 ET · replay FSLR in the terminal
Spot
177.8
from put-call parity
Zero gamma flip
169.9
4.4% below spot
Call wall
177.5
0.2% below spot
Put wall
180
1.2% above spot
Net gamma, volume
+$1M
per 1% move
Net gamma, OI
-$9M
per 1% move
Price sits above the flip at 169.9: on this book dealer hedging leans against a move rather than adding to it. The call wall and the put wall stand on crossed strikes today, which happens when one expiry dominates the book; read the ladder, not the two labels.
The session, 2026-09-25 priceflipcall wallput wall
177.5180169.9177.8 net gamma, volume book09:3010:3011:3012:3013:3014:3015:30
day09-2509-24 9 points · volume book · levels drawn as they stood
Strikes through the day levelchange since the open absorbs a movefeeds itprice
202.5200197.5195192.5190187.5185182.5180177.5175172.5170167.516516015515009:3010:3011:3012:3013:3014:3015:30
Gamma by strike, two books on one axis
OPEN INTEREST · last close
STRIKE
VOLUME · today
202.5
200
197.5
195
192.5
190
187.5
185
182.5
180
put wall
177.5
call wall · spot
175
172.5
170
167.5
165
160
155
By expiry, volume book
expiryflipcallputnet
2026-09-25 · 0DTE186177.5180-$231K
2026-10-02158.4190177.5+$815K
2026-10-09173.7200160+$37K
2026-10-16161.4185165+$246K
2026-10-23n/a165175-$117K
2026-10-30n/a180155+$350K
How far to trust this bookD

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

Prints a second, regular session0.13
Strikes where the two books agree on the sign67%
Contracts traded today, expiries shown13,352

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.
  • FSLR 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 FSLR, 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 FSLR 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.