Bitcoin options show downside convexity ahead of FOMC meeting

Bitcoin traders are quietly bracing for impact. Options markets heading into the September 15-16 FOMC meeting showed a clear put skew, meaning implied volatility on 25-delta puts ran higher than the equivalent calls. When protection costs more than participation, the market is telling you something.

The gap was not dramatic, but it was deliberate. The 25-delta put skew for the September 25 expiry came in about 1.44 percentage points above comparable calls, according to positioning data from the period.

What the skew actually means

When puts carry higher implied volatility than calls at the same delta, market makers are pricing in asymmetric demand: more buyers want downside protection than upside exposure at equivalent strike distances from spot.

In this case, Bitcoin was trading near $80,000 heading into mid-September, and the broader options surface reflected cautious sentiment rather than outright panic. Overall implied volatility, as tracked by the DVOL index on Deribit, sat around 38.9% for near-term contracts on September 16. That is a moderate reading, not the kind of elevated fear gauge you see during genuine liquidation spirals.

Open interest told a similar two-sided story. Calls still dominated, comprising roughly 61% of total open interest versus 39% for puts. The put skew existed not because bears had taken over the book, but because a meaningful subset of traders was willing to pay a premium for insurance on short-dated contracts specifically.

Elevated put premiums on near-term expiries, against a backdrop of call-heavy aggregate positioning, points to event-driven hedging rather than a broad structural shift toward bearishness.

The FOMC effect on crypto options

Earlier in 2026, around the July FOMC window, the dynamic was noticeably different. Near-term put hedges were unwound during that period, compressing the 25-delta skew to around 4%. The September reading represented a material step-up in defensive positioning relative to that summer baseline, suggesting the market’s risk perception had shifted over the intervening months.

Reading the tea leaves for what comes next

The duality in the data, bullish aggregate positioning alongside elevated short-term put premiums, creates a complicated signal for anyone trying to predict post-FOMC price action. It does not cleanly say the market expects a sell-off. It says the market wants to be ready for one while keeping its upside exposure intact.

The asymmetry that traders paid to construct, higher IV on puts than calls, essentially locks in a scenario where downside moves could be faster and steeper than upside moves of equivalent magnitude. That is what downside convexity actually means in practice: the options market has been priced to accelerate bearish moves more than bullish ones in the short window surrounding the event.