Expiration cycles

The cycles

Deribit, OKX and Bybit list BTC and ETH options on the same calendar, with every expiry at 08:00 UTC:

• Daily: an expiry on most days, listed only a few days ahead;
• Weekly: every Friday;
• Monthly: the last Friday of each month;
• Quarterly: the last Friday of March, June, September and December, listed many months ahead.

The cycles overlap: the last Friday of September is a quarterly, a monthly and a weekly at once. BOSS labels each listed expiry by its date alone with the highest cycle it belongs to.

A worked example

On Thursday 1 October 2026 at 12:00 UTC, a typical set of BTC expiries looks like this:

Expiry	Days to expiry	Cycle
Fri 2 Oct	0.8	Weekly
Sat 3 Oct	1.8	Daily
Fri 9 Oct	7.8	Weekly
Fri 16 Oct	14.8	Weekly
Fri 23 Oct	21.8	Weekly
Fri 30 Oct	28.8	Monthly
Fri 27 Nov	56.8	Monthly
Fri 25 Dec	84.8	Quarterly
Fri 26 Mar 2027	175.8	Quarterly

Days to expiry count calendar days to 08:00 UTC, fractions included: crypto trades every day, and theta runs through the weekend.

Where the liquidity is

Volume and open interest concentrate in the monthlies and especially the quarterlies: they are listed longest, institutions and funds roll positions on them, and the largest strikes' open interest builds up there. Dailies and weeklies are busy close to the money and thin in the wings. In practice, that means tighter spreads and deeper books on the big expiries, and wider spreads on a weekly's far strikes (see bid-ask, slippage and fees). Large expiries can also attract the price toward heavily traded strikes in their last hours, the pin risk sellers watch for.

Choosing an expiry

The expiry sets a strategy's character. A short expiry has high gamma and fast theta: the position reacts sharply to moves and its premium decays quickly. A long expiry has more vega: it reacts to changes in implied volatility more than to the daily price. A calendar spread uses two expiries at once, and the term structure compares implied volatility across them.

When you open a strategy page or the Dashboard without choosing, BOSS picks the first expiry at least 7 days out (on the example date, 9 October). The nearest expiry is often less than a day away: there, the smile is dominated by near-zero-premium wings, a probability of profit says little, and a structure's fixed per-leg fees can be larger than its premium.