What you're looking atMarket makers who sell QQQ options have to hedge them by buying and selling the underlying. GEX (gamma exposure) estimates how much forced hedging sits at each strike, in dollars per 1% move. Where the piles are big, price behaves differently moving through them.
Call wall / put wallThe strikes carrying the largest positive and negative gamma. Price tends to slow, stall, or pin into a wall because dealer hedging leans against the move there.
What dealers do on positive daysWhen dealers are net long gamma, their book gains delta as price rises and loses it as price falls, so staying flat forces them to sell every rally and buy every dip. Real, mechanical flow leans against each move, which is why positive days pin, chop, and mean-revert, and why the walls hold: the closer price gets to a big strike, the harder the hedging pushes back.
What dealers do on negative daysWhen dealers are net short gamma it inverts: a drop makes their book longer, so they must sell into the decline; a rally makes it shorter, so they must buy into the rip. Their hedging now pushes the same direction as price, selling forces more selling. That's why negative days trend, tails run fast, and walls act as launch points instead of brakes.
Gamma flipThe price where net dealer gamma crosses zero, the switch between those two regimes. Above it, dips get bought and fades work; below it, hedging chases price and rallies are suspect until the flip is reclaimed. A decisive break of the flip on volume is one of the strongest intraday signals on the board. And the flip moves: fresh 0DTE positioning drags it around during the session, so the regime line tracks its drift, worth re-checking in the early afternoon, not just at the open. When no flip prints, the sign never crosses inside the strike range.
GTBR bandGamma-theta breakeven, roughly one expected daily move either side of the open. Dealers bleed on gamma when price moves but collect theta as time passes; inside the band the theta covers the bleed, so nobody is forced to do anything and even a negative-gamma day can chop quietly. Past either edge, gamma losses outrun theta and the forced hedging switches on. Think of it as the trigger: the regime tells you what kind of day it would be, the band tells you whether that day has started.
What the research says about the bandA 2024 study of dealer books found the forced-hedge momentum only shows up once price has crossed the breakeven band, however short gamma the dealers were; days that never leave it tend to fade their own move into the close instead. The push is strongest when the break is to the downside and roughly twice as strong in expiry week, and it peaks near the edge itself: once price is far beyond it, the hedge has mostly been done. So treat the band as the trigger, not the target.
Flow checkThe standing book (open interest) versus what actually traded today (volume). When both agree, trust the regime at full conviction. When the standing book is positive but today's flow is selling, the regime may be turning, expect false breaks. When a negative book meets heavy buying flow, squeezes get violent.
Major wallThe single biggest gamma concentration on the whole board, the session's gravity point. Above spot leans the tape upward, below leans it down. If it relocates during the day, the regime line says so; that shift usually means large positioning changed, so respect the new location over the morning one.
Why a wall breaksWalls get run over for a reason. The regime decides first: in positive gamma dealers lean against price at the strike, in negative gamma the same strike becomes fuel once it gives. Size decides second: hedging flow is mechanical and has no conviction, so a macro print or a block order simply bigger than the pile pushes through, and once through there is usually nothing resting behind it, which is why breaks look violent rather than gradual. Then the tape: slow price, absorption and rejection wicks mean the level is being defended; fast, one-sided volume with no hesitation means real flow is winning and the wall is about to fail. Gamma shows you where to watch; order flow shows you whether it is holding.
Walls decay through the day0DTE gamma bleeds out as the session ages. A level that looked solid at the open can mean little by early afternoon, while fresh open interest builds at new strikes. That is why the board is recomputed every 15 minutes and republished pre-open, mid-morning and pre-close: yesterday's wall, or this morning's, can simply stop mattering once the size has rolled elsewhere. One more thing the table will show now and then: a put wall printing above the call wall. That is not an error. A wall is the biggest strike of its sign, and spot can run past it.
Charm into the closeAs the day ages, time decay alone drains delta out of options, forcing dealers to adjust hedges even if price sits still. On 0DTE this flow dominates the last 90 minutes, after about 2pm the walls fade in importance and the charm lean in the regime line carries the close.
RegimeNet positive gamma: dealers absorb flow, expect chop and mean reversion. Net negative gamma: dealers amplify flow, expect trend and fast tails. The regime line above reads this for you on every print. One honest caveat: dealer positioning is inferred, not observed, treat every level as a zone that needs live price confirmation, not a line that trades itself.
0DTE vs Swing0DTE reads only today's expiry, where hedging pressure is most violent intraday. Swing stacks the later expiries out to roughly 60 days for the bigger structure.
Γ1 to Γ10The ten biggest gamma concentrations on the board, ranked by absolute size, either side of spot. These are the magnet and brake candidates beyond the walls.
NQ mappingEverything is computed on QQQ, then mapped onto NQ with a live-refit ratio: —. The ratio is re-fit from live prices on every print, so NQ levels stay honest as the spread drifts.
How often it refreshesThe worker recomputes the whole board from the live QQQ option chain every 15 minutes through the trading day (CBOE data is ~15 minutes delayed). This page re-pulls every 5 minutes while open, and the GEX tab shows an orange dot whenever a new print lands that you haven't seen. Last print: —.
