Bitcoin options traders lean into upside as short-dated calls gain favor

Bitcoin options traders are paying up for the right to profit if prices rise. At the one-week, 25-delta level, demand for calls is now running ahead of demand for puts.

A call option pays off if Bitcoin rises, and a put pays off if it falls.

The "25-delta" label refers to options that sit a moderate distance from the current price. Traders compare the implied volatility of 25-delta calls against 25-delta puts. The gap is called the risk reversal, or skew. When puts cost more, the market is paying for crash protection. When calls cost more, traders are paying for exposure to a rally.

The broader 25-delta skew turned positive on August 20, 2026. That was the first bullish tilt in roughly 12 months.

By mid-September 2026, calls made up approximately 61.4% of total Bitcoin options open interest, with puts accounting for 38.6%. Data from Derive put call open interest at around 305,530 BTC.

In the 24-hour volume figures around the initial bullish signal, calls led puts.

In late September, a Derivasys snapshot showed the one-week 25-delta risk reversal rising 1.07 vol points to -0.24. That reading moved from clearly favoring downside protection to roughly neutral within a single snapshot.

Further out on the curve, traders have stacked larger call open interest at the $80,000, $85,000, and $100,000 strikes for December expiries.