Where to find today's SPX net GEX value
If you searched for today's SPX net GEX, you want a number, not a lecture. The number is one click away: SquawkFlow's free SPX GEX dashboard publishes today's net gamma exposure in dollars of dealer gamma per one-point move in the index (gamma times open interest times the contract multiplier times spot, calls positive, puts negative), beside spot, the call wall, the put wall, the zero-gamma flip and the current gamma regime. No account, no paywall. The page states, in a dated sentence, which session's settlement open interest the figure was computed from and how many contracts went into it, and the same figures live in a plain-text version at squawkflow.com/gex.md if you want to pull them into a script.
The rest of this page covers the part no dashboard hands you: what a "today" number actually is, and how to read the one you just found. If you want the mechanics of gamma exposure itself, that is a different article. What is gamma exposure covers the concept, and SPX gamma levels covers the full board of levels this number sits on.
Every "today" number carries three timestamps
A current net GEX value sounds like a single fresh fact. It is really three layers of freshness stacked together, and they age at different speeds. Knowing which layer a dashboard is dating is most of the skill in using one.
The open interest vintage. Open interest, the positioning input, settles once per session. Every GEX dashboard in existence, free or paid, builds today's number on the option book as of the previous close. That is structural, not a vendor shortcut: nobody clears intraday open interest. The practical consequences, and the checks that follow from them, are the subject of our free gamma exposure chart guide.
The snapshot time. This is when the model was last recomputed against the market. Spot and implied volatility move all day, so the same fixed positioning produces a different net GEX at 2pm than it did at the open. Vendors differ here more than anywhere else. SpotGamma's free SPX chart says it is updated daily. QuantWheel's free tool computes a figure when you run it, capped at three free calculations per day. FlashAlpha's SPX page carries "Live Today" in its title while its own methodology note says positioning updates after the market close, around 8:30pm ET, from OCC-reported open interest. The disclosure is the honest part. The title is the part most searchers read.
SquawkFlow's number lives under the same constraint, and the page says so rather than hiding it. The net GEX figure is computed once each morning before the open, from a full-chain snapshot of Cboe settlement open interest across roughly 21,000 SPX contracts crossed with current implied volatility, and that headline figure then stands for the session. What refreshes every 30 minutes through the cash session is the market around it: spot, the expected range and the 0DTE magnet level, with the regime label updating if spot genuinely crosses the flip. The differentiator worth claiming is not a faster recompute, it is disclosure: the settlement date behind the number, the contract count, and a timestamped session log of what the structure did since the open, all on the page.
The page refresh. A widget that says "updated 5 seconds ago" is dating its own render, not the data behind it. A page can re-render every second on top of a snapshot that has not changed since last night.
The test that sorts dashboards in about ten seconds: look for the settlement date of the open interest. A tool that tells you which session's book it is standing on is treating you like an adult. A tool that shows only "seconds ago" is dating the wrong layer.
How to read the current value, in order
Once you have the number, read it in this order. Each step gates the next.
1. Sign before size. Positive net GEX means the model has dealers net long gamma, hedging against the move, which tends to dampen intraday swings. Negative means net short gamma, hedging with the move, which tends to amplify them. Everything else about the reading is refinement on that one bit. Remember what kind of claim it is, though: dealer positioning is an assumption, not an observable. Open interest shows that a contract exists, never which side a dealer holds, so every net GEX figure published anywhere, ours included, inherits that assumption. If the sign logic is unfamiliar, start with the primer linked above rather than trading off a number you cannot interpret.
2. Size it against its own recent history. There is no universal threshold where net GEX becomes "big". A reading only means something against the range of recent sessions, which is why a value with no history beside it is close to useless. One pattern from SquawkFlow's own session history is worth flagging: on the handful of days when two independent estimation routes disagreed about the sign, spot was sitting within roughly a quarter of a percent of the zero-gamma flip and the absolute reading was a fraction, less than a fifth, of its ordinary size. A small net GEX with spot pinned near the flip is not a weak positive or a weak negative. It is the model telling you the sign is not resolvable, in the least stable configuration the market offers. Our dashboard labels that state neutral rather than guessing, and a small near-flip reading on any vendor's chart deserves the same skepticism.
3. Treat it as a point, not a constant. Net GEX is evaluated at whatever spot its snapshot used. If SPX has moved 40 points since that snapshot, the number describes a configuration the market has already left, whether or not the dashboard has refreshed the widget around it. This is why the zero-gamma flip matters more than the headline value: it tells you where the sign changes, which survives the market moving. The current value tells you where you stand; the flip tells you what would have to happen for the regime to change.
4. Then the walls. The call wall and put wall locate where hedging pressure is concentrated, which is a different question from how much aggregate gamma exists. Reading them is covered in the SPX gamma levels guide linked above.
What today's net GEX cannot see
Same-day expiries are the blind spot. A 0DTE contract opened at 9:45am and closed by 3pm lives and dies inside the session, so it never reaches the overnight settlement file that tomorrow's open interest is built from, and it is invisible to the open-interest vintage today's number stands on. This is not a rounding error: Cboe reported that 0DTE contracts made up 60% of total SPX volume in September 2025, in a month averaging 4.26 million SPX contracts a day. The majority of the day's option flow, and the gamma it creates and destroys, happens off the books your current net GEX is reading. On heavy 0DTE days, treat any OI-based number, including ours, as a description of the standing inventory, not the whole battlefield.
If two sites disagree on today's number
They will, routinely, and usually neither is broken. Before deciding one is wrong, ask three questions. Are they standing on the same open interest vintage, or has one updated overnight while the other has not? Are they summing the same expirations, all listed dates versus near-dated only? And are they quoting the same units, dollars of gamma per 1% move versus per point, which differ by a factor of nearly eighty on an index near 7,700? Sign conventions add a fourth wrinkle, since a chart built on the opposite dealer-positioning assumption flips the sign of everything. The full reconciliation checklist is in the free chart guide; the short version is that a disagreement between two dashboards is almost always a disagreement between two model configurations, not a data error you can arbitrage.
Today's numbers for SPY and QQQ
The SPX dashboard is SPX-only, but SquawkFlow's gamma exposure heatmap publishes today's numbers for SPY and QQQ on their own pages, with each ETF's net GEX stated in dollars of dealer gamma per 1% move in that ETF. Both pages use the same convention, which is the units lesson in miniature: the heatmap and the SPX dashboard each state net GEX in dollars of dealer gamma per 1% move, matching what commercial vendors publish, and each page states its own book and coverage in its method note. Two cautions carry over. Compare each symbol's reading to its own history only: SPX and SPY dollar gamma sit on very different notional bases, so cross-symbol magnitude comparisons mislead. And the ETF numbers inherit the same open-interest vintage and the same 0DTE blind spot as the index number, so everything above applies unchanged.
The honest summary of "SPX net GEX today" is this: the current value is free and one click away, it was computed this morning from last night's settled book and holds for the session while spot and the levels around it move, and it is a point estimate whose sign, size relative to recent days, and distance from the flip are what actually change a decision. Check the number, check its date, and know which of the three timestamps you are trusting.
Educational content, not financial advice. See our risk disclosure.