What you are looking at
Open /t/btc/gex. The GEX profile charts estimated gamma exposure by strike, often with a naive sign (calls positive / puts negative or dealer-style assumptions). Walls mark large call or put concentrations. Flip is where modeled net gamma changes sign — a narrative level, not a law of physics. This is not a dealer inventory feed.
The dedicated GEX education article covers theory. This how-to is the desk: /t/{asset}/gex, workbench, and related heatmaps.
Index × IV field
The large heatmap on /t/btc/gex is the same naive OI×γ model, repriced on a grid of hypothetical index and a flat IV shock. Purple-to-red (negative) is modeled as slippery — hedge proxy sells into a decline. Teal (positive) is modeled as sticky. MIN/MAX are the current-IV column extrema. Hover shows a 1% hedge-proxy notional. This is not a dealer inventory feed.
X is a parallel IV applied to every listing; Y is hypothetical index ±20% of spot. Changing the expiry filter rebuilds the field from that slice of the chain.
How to read a session
Pick expiry scope (front versus all). The strike-profile bars under the field are the classic OI×γ chart. Note spot versus call wall, put wall, and flip. Ask whether those strikes also have real OI and tape, not just a pretty bar. Strike insight confirms one strike at a time.
If the model is naive OI × γ × S², changing expiry filters will change the story. That is expected.
What not to do
Do not buy because “flip support.” Do not sell a naked call because “call wall overhead.” Those are blog habits. Use GEX as one input after IV, liquidity, and your own risk cap.
Do not mix venues’ OI into one GEX without knowing the model’s aggregation. Multi-venue estimates can mix units if you are careless — inverse versus linear again.
Companion desks
Levels and heatmaps for visual clustering. Dealer-positions for related views. Tape to see if anything actually trades at the wall. Term/skew so you do not ignore the rest of the surface.
Category greeks-board stacks several of these on one page if you do not want to hop.
Honesty of the feed
If M aggregated GEX is offline, the desk should fall back to venue public OI and say so. Mock GEX is a layout, not a market. Sources desk: /t/{asset}/sources.
Partner feed names stay branded as M in the UI — no hostnames.
Next
Theory: /guides/gex. Practice: /t/btc/gex. Spot candles: /chart/BTC. Venue: still /v if you will trade a strike that sits on a wall.
Model limitation: this is not a dealer inventory feed.