Bitcoin BTC has mostly traded sideways since printing record highs above $110,000 last week.

The loss of upward momentum is now accompanied by signs waning bullish sentiment among market participants trading options tied to BlackRock's spot bitcoin exchange-traded fund (ETF).

That's evident from the one-year put-call skew, which reflects how the market prices in volatility risk for put options, offering downside protection relative to calls, representing bullish bets. Negative values represent a bullish bias while positive values suggest fears of downside.

IBIT's one-year skew has bounced to nearly zero from the four-month low of minus 3.8 two weeks ago, according to data source Market Chameleon . In other words, IBIT options traders are no longer chasing upside via options.

Perhaps they are expecting a pullback. Similar mood is evident in Deribit-listed options where the short-term call skew has weakened, meaning calls expiring in the next two weeks are trading at par with puts, according to data source Amberdata.

Read more: Bitcoin's $95K-$105K Range in Focus as $10B BTC Options Expiry Looms