Nearly $2.5 billion in Bitcoin and Ethereum options expire today, setting up a potentially volatile end to the month as traders juggle upside bets with deep downside insurance.

On the surface, positioning appears constructive. But beneath the call-heavy skew lies a striking anomaly: one of the largest open interest clusters in Bitcoin sits far below spot — at the $40,000 strike.

Bitcoin is currently trading around $67,271, with max pain positioned at $70,000. Open interest shows 19,412 call contracts and 11,044 put contracts. This gives a put-to-call ratio of 0.57 and reflects an overall upside bias. The total notional volume tied to the expiry is roughly $2.05 billion.