Surging volumes in put options linked to BlackRock’s Nasdaq-listed spot bitcoin ETF (IBIT) could be interpreted as bearish sentiment. That’s not necessarily the case.

On Friday, more than 13,000 contracts of the $30 out-of-the-money (OTM) put option expiring May 16 changed hands as the ETF rose 1.7% to $57.91, according to data from Amberdata. Volume in the $35 put option expiring Jan. 16, 2026, topped 10,000 contracts.

Most of the activity probably stems from market participants looking to generate passive income through “cash-secured put selling” rather than outright purchase of the options as bearish bets, according to Greg Magadini, Amberdata’s director of derivatives.

A put seller, offering insurance against price drops in return for a premium, is obligated to purchase the underlying asset at a predetermined price on or before a specific expiration date. (That’s opposed to the buyer of the put, who has the right but not the obligation to sell the asset.)

That means savvy traders often write OTM puts to acquire the underlying asset at a lower price while pocketing the premium received by selling the put option. They do so by continuously maintaining the cash required to purchase the asset if the owner of the put option exercises their right to sell the asset.

Hence, the strategy is called “cash-secured” selling of puts. In IBIT’s case, sellers of the $35 put expiring in January 2026 will keep the premium if IBIT stays above that level until expiry. If IBIT drops below $35, the put sellers must buy the ETF at that price while keeping the premium received. The sellers of the $30 put expiring in May next year face a similar payoff scenario.

“The $35 Puts for Jan 2026 traded +10k contract with an IV range of 73.52% to 69.94%, VWAP at 70.75% suggests net selling from the street… potentially Cash Secured put selling flows (for traders who missed the rally),” Magadini said in a note shared with CoinDesk.

Saxo Bank’s analyst suggested cash-secured put selling as the preferred strategy in Nvidia early this year.

Calls are pricier than puts

Overall, IBIT call options, which offer an asymmetric upside to buyers, continue to trade pricer than puts.

As of Friday, call-put skews, with maturities ranging from five to 126 days, were positive, signaling relative richness of implied volatility for calls. The bullish sentiment is consistent with the pricing in options tied to bitcoin and trading on Deribit.

On Friday, IBIT recorded a net inflow of $393 million, representing the majority of the total inflow of $428.9 million across the 11 spot ETFs listed in the U.S, according to data tracked by Farside Investors.