The gamma flip is a single price level that decides which way dealer hedging pushes the market. Above it, dealers absorb moves and price tends to mean-revert. Below it, dealers chase moves and price tends to trend.
It's one number. It changes the entire complexion of how a stock trades. Knowing where it sits, and which side of it spot is on, is the single most useful regime read in options.
What dealer gamma actually is
Every option a dealer is short has a hedge underneath it — some amount of the underlying stock held to stay neutral on direction. As the stock moves, the size of that hedge has to change. Gamma is just the rate at which the required hedge changes per dollar move in the underlying.
Two facts about dealer gamma carry the whole concept:
- Across their entire book, dealers are either net long gamma (their position gains as the underlying moves either direction) or net short gamma (their position loses as it moves).
- Their hedging behavior flips depending on which side they're on — and that flip is what shows up on a chart as the difference between pinning and trending.
The two regimes
When dealers are net long gamma, hedging is mean-reverting. To stay flat as price rises, they sell shares back into the rally; to stay flat as price falls, they buy shares back into the decline. The net effect is that dealer flow dampens volatility. Price action tends to pin around heavy strikes, and walls behave like real obstacles.
When dealers are net short gamma, hedging is trend-amplifying. To stay flat as price rises, they buy MORE shares; to stay flat as price falls, they sell MORE shares. Dealer flow becomes procyclical. Volatility expands. Price runs further than the chain suggests it should, and walls are more likely to break decisively rather than hold.
The gamma flip is the spot price at which the dealer book switches from net long gamma to net short gamma. Above the flip, the book is net long gamma — pinning regime. Below the flip, the book is net short gamma — chasing regime.
GEX (Gamma Exposure) is the aggregate dealer gamma at the current spot, in dollars per 1% move. When GEX is positive, you're above the flip; when it's negative, you're below. The flip is just the level where GEX crosses zero.
What it looks like on a Runir page
Every Runir card carries a regime label derived from the flip. On NVDA today, the flip sits near $189.58. The page surfaces the live distance from spot and the regime label that derives from where current spot sits relative to it — when spot is above the flip, the page frames the walls as defended levels rather than chase points.
The same flip number shows up in two places:
- On every per-name page, in the levels block below the walls, with the regime label sitting near the top of the card.
- On the gamma board, where the universe is sorted by flip distance — the names most-above-flip pin hardest, the names most-below-flip trend hardest. One scan and you know which side of the regime each name is operating on today.
Pair the flip with the call wall above and the put wall below, and you have the three numbers that explain why a stock is doing what it's doing. The call wall piece covers the upper level; the put wall covers the lower.
What it doesn't tell you
The flip is computed from a snapshot of open interest on the chain. Large repositioning — a block trade, a major hedge unwind — can move tomorrow's flip by a meaningful percent. The flip is a level for the session it's published for, not a static line.
The flip is also a regime indicator, not a directional one. A pinning regime says “expect mean-reversion against the walls.” It does not say go long. A chasing regime says “expect volatility expansion.” It does not say go short. The regime gives you the backdrop — what each wall actually means depends on which regime you're reading it in. That's why the flip and the walls only make sense as a set.
The rate at which our regime calls correctly predicted the next session's character lives, with sample size attached, on the methodology page. We publish that because anyone publishing regime calls without the accuracy behind them is asking you to take their word.
How to read the card
Open the gamma board and the universe is ranked by flip distance — pinning names at the top, chasing names at the bottom. Click into any name and the per-page levels block shows the specific flip price, the regime label, and the walls that anchor each regime's expected behavior.
The next stop is the put-wall explainer — the floor that makes the regime read complete — or jump back to the call-wall piece if the upper level is what you came for.