The first Bitcoin-linked exchange-traded fund (NYSE: BITO US) listed in the U.S. debuted as the second-most heavily traded fund on record in a watershed moment for the crypto industry. The ProShares Bitcoin Strategy ETF -- trading under the ticker BITO -- rose about 4.9% to $41.94. More than 24 million shares changed hands Tuesday, according to data compiled by Bloomberg. With turnover of almost $1 billion, BITO’s debut ranked only behind a BlackRock carbon fund for a first day of trading.