Cathie Wood's Ark Investment Management said in an e-mail it bought 78,982 shares in cryptocurrency exchange Coinbase (COIN), its first investment in the crypto exchange in a month.

At Friday's closing price of $40.24 , the purchase would have cost about $3 million. The stock has been in a funk in recent months, and is down almost 60% from $98 in early August.

(By Jamie Crawley)