The ProShares exchange-traded fund, which started trading in October 2021 as the first U.S. bitcoin-linked ETF, now accounts for 5.03% of the ARK Next Generation Internet ETF (ARKW), its sixth-largest holding. The fund no longer holds any GBTC shares, with the last reported sale on Dec. 20. At just under 12%, Coinbase remains the fund’s largest holding even after Wednesday’s sale of 148,885 shares.