NEW YORK — Unusual Whales has updated its gamma exposure tool, giving traders a direct view of where market makers must hedge and how that hedging pressure maps across strike prices. The centerpiece of the update is a feature called Periscope, which runs exclusively on data fed straight from CBOE—the only exchange where SPX options trade.
Gamma exposure, or GEX, measures the estimated dollar value of shares that market makers need to buy or sell as the underlying price moves by one percent. The concept rests on how market makers accumulate inventory: because they act as the counterparty to nearly every options transaction, they end up holding long calls—bought from investors who sell calls for income—and short puts, sold to investors seeking downside protection. That inventory creates directional risk the market maker never wanted, and they neutralize it by trading shares of the underlying stock.
The direction of that hedging determines whether GEX stabilizes or amplifies price moves. When GEX is positive, market makers sell into strength and buy into weakness, which compresses volatility. When GEX is negative, they do the reverse—buying as prices rise and selling as prices fall—which pushes moves further in the direction they are already heading.
Periscope is the only tool in the Unusual Whales suite that bypasses the core assumption problem. Every other GEX tool—on Unusual Whales or anywhere else on the internet—derives its estimates from raw volume or raw open interest figures. That approach requires the tool to assume who is on which side of each trade. Periscope skips that step entirely because the CBOE dataset shows the actual buy and sell data, not a statistical inference around it.
The CBOE data stream also identifies whether an order came from a customer or from a market maker, and Periscope filters its output to show only market maker positioning. That separation removes a large portion of the noise that makes other GEX readings unreliable: retail and institutional customer orders get excluded, leaving only the hedging activity that actually drives mechanical price support and resistance.
SPX's exclusive listing on CBOE is what makes this possible. A ticker like SPY trades across more than a dozen different options exchanges, so no single exchange holds the complete tape. Because every SPX contract clears through CBOE, that one dataset captures the full picture. No other underlying offers this—Periscope is explicitly built around SPX for this reason.
Subscription tier determines how frequently the data refreshes. Retail Pro subscribers receive a 10-minute refresh on the Periscope feed. Retail Max subscribers receive a one-minute refresh, which is close enough to real time to be actionable during fast intraday moves.
Beyond Periscope, the platform ranks three additional GEX methodologies in descending order of signal clarity. The open interest view is the baseline—it shows aggregate positioning at each strike across expirations. The intraday volume view improves on that by substituting fresh same-day flow for accumulated open interest, making it more responsive to positioning shifts that happen during the session. The third method, which Unusual Whales calls Directionalized Volume, adds side attribution to the intraday volume data—meaning it attempts to separate buy-side from sell-side pressure within the day's flow, adding granularity that the raw volume count does not carry.
The platform also includes a Spot Gamma Heatmap, available with any paid subscription tier. The heatmap maps every active strike and expiration date for a given underlying, shaded by the intensity of dealer hedging required at each level and the direction that hedging pushes prices. It functions as a visual version of what the strike-level GEX numbers describe in tabular form: zones where mechanical buying or selling is likely to cluster around key expirations.
Separate from GEX, Unusual Whales surfaces three related Greek exposure views. Delta exposure, labeled DEX, shows the net directional bias of outstanding options positions—essentially a read on whether the aggregate book is positioned bullishly or bearishly. Vanna tracks how much delta changes as implied volatility shifts, which matters most when the VIX moves sharply. Charm measures how delta decays over time, capturing the hedging adjustments that market makers make as expiration approaches even when the underlying price does not move.
The practical value of the full GEX framework for equity traders is that it identifies price levels where dealer hedging is likely to create natural support or resistance around expiration dates. Those zones do not guarantee price behavior, but they describe where mechanical buying or selling pressure will concentrate if the underlying drifts toward a heavily loaded strike—information that is not visible in a price chart alone.
