gamma dynamics

Bitcoin’s September 11 options expiry on Deribit involved $2.24 billion in notional exposure, but price action diverged from patterns documented in peer-reviewed research on derivatives-driven reversals. The mismatch raises questions about whether historical gamma-driven dynamics still influence spot prices during major settlement events.

• $2.24 billion in Bitcoin options expired on Deribit’s Sept. 11 settlement, split between $1.40 billion calls and $844 million puts.
• Bitcoin declined 0.16-0.18% immediately before expiry at 08:00 UTC, rebounded 0.19-0.21% within the following hour, then fell again by press time.
• A peer-reviewed study found statistically significant reversals after expiries when at-the-money open interest ranked in the top decile, but current market-data dashboards show no matching negative gamma conditions.

• $2.24B Total notional value of Bitcoin options expiring on Deribit’s September 11 settlement
• $77,234 Deribit’s official delivery price, calculated as 30-minute time-weighted average index price
• $76,000 Bitcoin’s intraday low into the European afternoon trading session Friday
• 1,059 Number of Deribit expiry days studied from January 2021 through December 2023

Bitcoin fell into Deribit’s September 11 options expiry and initially rebounded after settlement, but the move did not persist. A $2.24 billion options contract set, comprising $1.40 billion in calls and $844 million in puts according to PerpFinder data at 06:40 UTC, created a significant derivatives event. The settlement process, which calculates the delivery price as a 30-minute time-weighted average of Deribit’s Bitcoin index from 07:30 to 08:00 UTC sampled every four seconds, resulted in an official price of $77,234.

Options expiry events have long been monitored by traders and researchers as potential inflection points in cryptocurrency markets. The concentration of expiring contracts at a single price point can create temporary hedging pressures, as options sellers and buyers unwind positions or allow contracts to settle. Understanding whether these settlement events systematically move prices has become increasingly important as cryptocurrency derivatives markets have matured and grown in size and sophistication.

The Intraday Price Sequence Around Settlement

Bitcoin’s behavior around the 08:00 UTC expiry timestamp resembled only a partial match to documented patterns in derivatives-driven markets. From 07:00 to 08:00 UTC leading into settlement, Bitcoin declined roughly 0.16% to 0.18% across Deribit perpetuals, Coinbase spot, and Kraken spot venues. The sell pressure pushed price as low as $76,000 into the European afternoon trading session.

During the hour following expiry, from 08:00 to 09:00 UTC, Bitcoin rebounded approximately 0.19% to 0.21% across the same three venues.

However, the rebound failed to hold. From 08:00 to 10:00 UTC, the broader post-expiry window saw losses resume: Deribit’s perpetual slipped 0.014%, Coinbase fell 0.025%, and Kraken declined 0.038%. Bitcoin therefore ended slightly below its expiry-time level across all three venues, settling near $77,500 by press time.

The pattern of an initial decline followed by a brief rally and subsequent renewed selling is not uncommon in spot markets following options settlement. Market participants often cite the expiration of hedges and the resolution of gamma-related pressures as reasons for post-settlement volatility. However, the precise mechanics and predictability of these movements remain subjects of ongoing debate among academic researchers and market practitioners.

Divergence From Peer-Reviewed Research On Gamma Effects

A peer-reviewed study published in Finance Research Letters examined 1,059 Deribit expiry days spanning January 2021 through December 2023 using five-minute returns. The research found a statistically significant pattern: Bitcoin tended to fall in the hour before expiry and reverse during the following two hours when at-the-money open interest ranked in the sample’s top decile, with the effect strongest under negative cumulative gamma conditions.

Gamma, a second-order Greek in options pricing, measures the rate of change of delta as the underlying asset moves. Negative gamma conditions can create incentives for options market makers to sell into price rallies and buy into price declines, theoretically amplifying price swings near expiry. When cumulative gamma across all options contracts reaches sufficiently negative levels, the theory suggests this hedging behavior could manifest as measurable distortions in spot prices.

Friday’s price action matched the initial decline but not the sustained reversal predicted by the study’s model. The research inferred market-maker positioning by estimating a gamma proxy from contract trading history and trade-initiation assumptions, rather than relying solely on total open interest or put-call ratios. Yet three market-data dashboards tracking current conditions, Optionly, CryptoGamma, and ByKaranteli, did not display a negative cumulative gamma proxy near spot price on the expiry date.

The disconnect suggests either that the historical pattern has weakened in 2024 or that current market structure differs from the conditions that produced the original research findings.

What Remains Unresolved About Derivatives Influence On Spot

The study’s strongest predictive condition could not be verified with publicly available data from current market snapshots. The at-the-money open-interest threshold that ranked in the sample’s top decile during historical expiries could not be matched against Friday’s actual market conditions. This gap raises an open question: whether the peer-reviewed pattern reflects genuine market-maker gamma dynamics that still operate today, or whether it represents a historical artifact no longer present in current market structure.

Changes to market participants, trading infrastructure, and risk management practices since 2023 could all plausibly reduce or eliminate the pattern that researchers previously documented. Increased algorithmic trading, improved risk management tools, and the entrance of institutional participants with sophisticated hedging programs may have dampened the systematic price distortions that once characterized options expiries.

Monitoring whether future Deribit expiries produce reversals after settlement, and whether gamma dashboards eventually register the negative conditions associated with the historical pattern, will clarify whether derivatives-driven price dynamics have fundamentally shifted or whether the mismatch reflects methodological differences between the study’s reconstruction and live market data.