BTC and ETH options carrying roughly $18.1 billion of notional value are scheduled to expire Friday, Sept. 25, according to a Coinbase Markets snapshot. Calls outnumber puts in both assets, with the recent Bitcoin trading mix even more tilted toward calls than the outstanding book. The expiry is large enough to focus attention on major strikes, but $18.1 billion is not a forecast of spot purchases or cash changing hands that morning. Positions can be closed, rolled or hedged before settlement. The defensible question is where exposures concentrate and how hedges behave as prices approach the 08:00 UTC fixing.
BTC and ETH options show a call-heavy book
Coinbase Markets put the Bitcoin open-interest put/call ratio at 0.66 and the 24-hour volume ratio at 0.37. Ether's corresponding readings were 0.61 for open interest and 0.55 for trading volume. A value below one means calls exceed puts by the chosen measure. A lower volume ratio for BTC suggests more calls than puts traded recently, relative to the book already outstanding. It does not disclose whether those calls were bought or sold, and many positions form part of spreads rather than outright bullish wagers.
A separate Deribit-sourced snapshot at 03:53 UTC on Sept. 23 showed around $16.13 billion of Bitcoin options and $2.16 billion of Ether options due Friday, or approximately $18.29 billion together. That differs modestly from Coinbase's $18.1 billion figure. Prices, contract positions and the time at which a snapshot is taken can all affect reported notional values. The two readings should not be treated as rival claims that every outstanding option has exactly the same value at every moment.
Bitcoin accounted for most of the book. The later snapshot placed BTC call open interest near $9.61 billion against $6.52 billion in puts. Coinbase highlighted $90,000 and $100,000 as strikes with sizeable calls. BTC traded near $86,500 in the associated market snapshot, leaving $90,000 a few percent above spot and $100,000 substantially farther away. A large call position at a strike does not require the underlying price to reach it. Traders may hold the position as a hedge or as one leg of another structure.
Ether positions cluster farther above spot
Ether showed about $1.34 billion in call open interest and $820 million in puts at the later snapshot. Coinbase pointed to calls between $3,000 and $4,000. ETH was around $2,760 at the time, putting the lower end of that range roughly 9% above spot, while $4,000 was much farther away. A strong price run into the quarterly expiry would change the sensitivity of some options, but the current strike map does not establish where Ether will close on Friday.
The recent BTC and ETH rallies are part of why the notional number can grow even without an equal amount of new investment. Open interest valued in dollars can change as the underlying price changes. Coinbase previously placed combined expiry exposure near $16.6 billion in a Sept. 15 update, with BTC around $14.73 billion and ETH about $1.92 billion. The earlier quarterly-expiry snapshot is a useful comparison. Subtracting $16.6 billion from $18.1 billion does not show $1.5 billion of fresh cash deposits, because contracts and the underlying assets can both be revalued.
Put/call ratios also rose from those earlier readings, when BTC was 0.52 and ETH 0.57. That means puts had increased relative to calls under the respective open-interest snapshots, though calls still led both markets. It is possible for a book to remain call-heavy while becoming less so. Traders looking only at the 24-hour flow might miss that distinction.
Friday's 08:00 UTC settlement is a fixing, not a dump
Deribit schedules quarterly BTC and ETH options to expire on the last Friday of March, June, September and December at 08:00 UTC. The delivery price draws on an index over the period leading into expiry rather than a single isolated trade. Some market participants adjust futures and spot hedges before the fixing, particularly if a large position's sensitivity changes near a major strike. Others have already neutralized their exposure. The exact net effect depends on the direction of dealer positions and counterparties' trades, neither of which can be read from a headline notional amount.
Bitcoin's rise from around $76,000 on Sept. 17 to above $86,000 brought the market closer to $90,000 calls. Ether had also climbed from around $2,416 on Sept. 16. Those moves may lead participants to roll contracts or alter hedges as expiry approaches. The distinction between futures activity and spot buying matters here: derivative positioning can change quickly without a matching long-term accumulation of the underlying asset.
A Friday expiry does not mechanically send the full notional amount through spot markets. A trader can close a position beforehand; a spread can offset another exposure; and cash-settled obligations can be far smaller than the reference value of the underlying contracts. Traders should watch actual volume, changing open interest and funding conditions rather than infer a guaranteed price shock from the $18.1 billion estimate.
What to monitor before the fixing
The final total can still change as customers close, roll and open options between Wednesday and Friday. Compare the outstanding book near the fixing with Coinbase's earlier snapshot, check whether spot price approaches a heavily populated strike, and separate premiums, margin and notional exposure. Those measures answer different questions. Growth in crypto derivatives venues provides broader context, but it cannot tell you which side of Friday's Deribit book is positioned to buy or sell spot.
The headline figure describes exposure scheduled to end, not a bill the market must pay in full. Friday's more revealing data will be the contracts still open just before 08:00 UTC and the price at which the settlement window actually closes.
