By Dan Weil After a few days of quiet trading, Cathie Wood is back to dealing big names in big amounts. Her flagship fund has risen recently. After a few days of quiet trading, star investor Cathie Wood, chief executive of Ark Investment Management, is back to dealing big names in big amounts. On Friday, Ark funds in particular sold shares of electric-vehicle leader Tesla (TSLA) – Get Tesla Inc Report and bought into Nio NIO, the Chinese EV producer. (All valuations are as of Friday’s close.) The asset manager also bought Coinbase (COIN) , Roblox (RBLX) – Get Roblox Corp. Class A Report, Roku …