Cathie Wood's ARK exchange-traded funds snapped up shares of DocuSign during the 42% nosedive for the online-signature company, according to the firm's disclosures. Led by the ARK Innovation ETF ARKK, +1.52%, the funds bought $107.2 million shares of DocuSign, while the Innovation ETF sold $124.7 million worth of Tesla TSLA, -0.59% shares on Friday.