Bitcoin is heading into the expiry of options worth about $16bn on Deribit at 08:00 UTC on Friday, Sept. 25, with two US economic releases and the settlement of CME’s September futures due later the same day.
The expiring contracts comprise roughly $9.6bn in calls and $6.4bn in puts. Bitcoin was trading near $86,300 after moving above $85,000 this week, placing the market close to several important strike levels.
The expiry follows a major event in the equity market. Ledn co-founder Mauricio Di Bartolomeo described September’s quarterly expiry as the second part of a cycle that began with options on BlackRock’s iShares Bitcoin Trust (IBIT), which expired last week in the fund’s biggest single expiry on record.
He said that book was heavily weighted towards calls. As Bitcoin rose through $80,000, many of those contracts moved into the money, prompting dealers who were short them to buy IBIT shares as a hedge. Once new shares were required, authorised participants bought spot Bitcoin for the fund.
Di Bartolomeo expects a similar mechanism to influence Friday’s Deribit expiry.
“If the move continues, the large call blocks at $85,000 and $100,000 are where the same dynamic kicks in on the Deribit book,” he said in a note to CryptoSlate.
Calls account for about 60% of Friday’s open interest, although exchange data does not show which side dealers occupy. ByKaranteli’s open-source gamma model, based on one possible hedging assumption, identifies $95,000 as the largest call concentration and $60,000 as the biggest put concentration. It places the put-to-call ratio at 0.52 and the zero-gamma level near $71,000.
Above that level, dealers who are long gamma tend to sell into rising prices and buy declines, helping to dampen volatility. Below it, short-gamma hedging can amplify moves. With Bitcoin around $86,000, the model currently places the market in a stabilising positive-gamma zone.
Deribit’s DVOL index was 38.1 on Sept. 22, described by ByKaranteli as very low over five years of data. Friday’s at-the-money implied volatility was also 38.1%, while 25-delta puts and calls were both priced near 39.2%, indicating almost neutral skew.
Options pricing implies a move of about $2,720, or 3.15%, through expiry, giving an approximate range of $83,600 to $89,100. That puts $90,000 just beyond the expected band and $95,000 further away.
Deribit calculates its settlement price from a 30-minute time-weighted Bitcoin index average between 07:30 and 08:00 UTC. US durable goods orders are released at 12:30 UTC, followed by the University of Michigan’s final September consumer sentiment reading at 14:00. CME’s September Bitcoin futures settle at 15:00 against the CME CF Bitcoin Reference Rate.
The Federal Reserve raised its target range to 3.75% to 4.00% on Sept. 16, keeping both data releases relevant to rate-sensitive assets.
US spot Bitcoin ETFs recorded inflows of $159.5m on Sept. 17, $433m on Sept. 18 and $999m on Sept. 21, according to Farside Investors. Monday’s rise also included $647.9m in short liquidations, from $746.6m in total liquidations, while aggregate crypto open interest increased 7.59% to $156bn.
A 2026 Finance Research Letters study found statistically significant intraday reversals around Deribit expiries, particularly when at-the-money open interest was high and estimated gamma exposure negative. ByKaranteli’s model currently shows the opposite conditions, although a sharp reversal within two hours of 08:00 UTC would resemble that pattern.
The rally’s next test will be whether ETF demand and moderate positive funding survive the expiry, the economic data and CME settlement. If they do not, Bitcoin could retreat towards $83,600, with $80,000 the next level below.
