Do 0DTE options actually move the market?

They can shape intraday behavior around heavy strikes, but Cboe's research suggests the flow is usually two-sided and the average net impact is small. Blaming every sharp move on 0DTE is not supported by the published data.

Why doesn't the VIX capture 0DTE activity?

The VIX is built from options roughly 23 to 37 days from expiry, so same-day contracts never enter the calculation. Cboe's VIX1D was created to measure one-day expected volatility instead.

Is a gamma squeeze the same as a 0DTE effect?

Related, not identical. A gamma squeeze is a feedback loop from dealers hedging aggressive call buying; 0DTE effects cover both damping and amplification, in either direction, within a single session.

Can retail traders see 0DTE positioning?

Same-day chain volume is visible through most brokers, but dealer positioning is only ever a vendor estimate built on assumptions. Treat those dashboards as models, not measurements.

Concept

0DTE Flow Effects

0DTE Flow Effects are Breadth, Sentiment & External Data concepts. A reference entry: the Library explains it rather than implements it.

What are 0DTE flow effects?

0DTE options are contracts with zero days to expiration: they expire the same session they trade. Since Cboe filled out the S&P 500 weekly expiration calendar in 2022, index traders have had a listed expiry every trading day, and same-day contracts have grown into a large share of index option volume, on many days roughly half of SPX volume in Cboe's published figures.

0DTE flow effects are the intraday footprints this activity leaves on the underlying market. Options this close to expiry carry extreme gamma near the money, so small index moves force large adjustments in market makers' hedges. When dealers absorb one-sided same-day flow, their re-hedging can dampen movement, buying dips and selling rallies when long gamma, or amplify it by chasing the move when short.

The effects are strike-local and short-lived: pressure concentrates around strikes with heavy same-day volume, builds through the afternoon, and disappears at the close when the contracts expire. Cboe's research has generally found the flow balanced enough that its average net impact is modest, but on days it tilts one way, sharp intraday accelerations and pins are widely attributed to it.

Why there's no indicator for this

Measuring 0DTE flow takes the options tape, not the underlying's chart: strike-by-strike same-day volume and open interest, trade prints classified as buyer- or seller-initiated, and greeks computed from implied volatility. None of that can be recovered from index price and volume, so no honest chart study can claim to display 0DTE positioning.

Vendors do sell intraday dealer-gamma estimates built from chain snapshots, and they are useful maps of where hedging pressure could sit. They remain proxies: the public tape never reveals who is long or short each contract, so every model assumes a customer-versus-dealer convention. A proxy can flag candidate magnet strikes; it cannot verify actual dealer inventory.

How traders use it

As an intraday regime read, paired with gamma exposure estimates to judge whether hedging is likely to pin the index or accelerate a break.
For level selection: strikes with outsized same-day volume are watched as magnets or barriers into the close, cross-checked with intraday internals like the TICK Index.
Around scheduled events: same-day activity clusters near CPI and FOMC releases, and one-sided flow can exaggerate the first move after the print.
As volatility context: the VIX measures roughly 30-day expectations and excludes same-day options, which is why Cboe launched a separate one-day gauge, VIX1D, in 2023.
For risk management: some traders cut size or widen stops on expiry-dominated days, the same logic crypto traders apply around liquidation clusters.

0DTE flows vs adjacent positioning reads

Gamma Exposure: Gamma exposure aggregates hedging pressure across all expirations; 0DTE effects are the same mechanics compressed into one session, so desks read them together.

Open Interest: Open interest is the overnight ledger of outstanding contracts; 0DTE impact rides on same-day volume that expires before it can ever print in OI.

Concept family

Breadth, Sentiment & External Data

63 concepts mapped · 63 in the Library