Hedge funds have swung their bitcoin-futures bets to the bullish side for the first time, a marked turn around from a few weeks ago, according to figures released on Friday.

The data from the Commodity Futures Trading Commission suggests a shift in sentiment among so-called “leveraged funds,” a category that includes hedge funds. Ever since late December, when the CFTC began publishing weekly reports on the new bitcoin-futures market run by Cboe Global Markets Inc., data had shown that these funds were bearish on bitcoin,...