Ark Invest bought shares of Block, Nvidia, Securitize and the 3iQ Solana Staking ETF on Aug. 17 while selling Roblox, Shopify, Palantir Technologies and Advanced Micro Devices, according to the firm's latest trade disclosures. The biggest buy was Block, with ARK Innovation ETF purchasing 182,899 shares and ARK Fintech Innovation ETF adding 8,772 shares. Nvidia was bought across five funds for a combined 101,356 shares, while ARK Fintech Innovation ETF bought 189,796 shares of Securitize and ARK also added 7,115 shares of the 3iQ Solana Staking ETF across two funds. The moves extended Ark's recent buying in crypto-, AI- and tokenization-related names, while the largest sale by share count was 592,227 Roblox shares from ARK Innovation ETF. The disclosures do not provide reasons for individual trades, so the transactions show portfolio positioning rather than an explicit forecast on any company's prospects.