Is SPY in long or short gamma right now?

What the two states mean

Market makers end up holding the other side of what traders buy and sell. To stay neutral they hedge in the underlying, and the direction of that hedging flips depending on whether their aggregate gamma position is positive or negative.

Long gamma — hedging leans against the move. Dealers sell into strength and buy into weakness, which tends to compress the range and make moves fade.

Short gamma — hedging leans with the move. Dealers buy as price rises and sell as it falls, which tends to stretch the range and make moves extend.

The boundary between the two is the gamma flip. Which side of it price sits on is what this tool reports.

Does the regime actually change anything?

We tested it rather than assert it. Across 100 trading days of our own stored levels, days that opened in short gamma ran 16–36% wider high to low than days that opened in long gamma. Three of the four index instruments cleared the usual significance bar; one did not.

The same study found that our own call wall and put wall held only 44% and 51% of the times price touched them — a coin flip, on levels we publish. The full study is here, failures included.

What is free here, and what is not

The regime is free and always will be. It is one piece of information: which side of the flip the market is on.

What it does not tell you is where the levels sit — the flip itself, the call wall, the put wall, per ticker, moving through the session. That is the paid part, because that is the part that takes a chain engine running every ten seconds across 30 tickers.

In between there is a free middle step: the weekly email sends you SPY's call wall and put wall once a week, for an address and nothing else.

How often this updates

Through the session, every few minutes. Outside it, the card says so plainly and reports where the structure stood at the last close rather than pretending to be live.

If the data stops arriving, the card hides itself instead of showing a stale state. An indicator that quietly goes out of date is worse than one that admits it has nothing.