Wood's Ark Investment Management has acquired more than 55,000 shares of the electric carmaker.
Tesla's loss of its star status in the ETF is a reminder of the pressure on growth stocks.
Sanctions on China have arisen as a possibility with news reports of Russia asking the nation for military help.
Traders have been piling into Treasurys and selling stocks as tension escalates near Ukraine's border.
Ark ETFs have bought Sea shares almost every day in February.
The selling comes amid a mixed set of results from its social-media peers
Wood and her firm frequently say that their investment horizon is at least five years.
Some of the world's biggest investors, including BlackRock and Franklin Templeton, say value's moment has arrived.
The move comes one day after Twitter founder Jack Dorsey announced his departure as CEO.
Ark Next Generation Internet ETF bought 158,350 shares of the online broker on Tuesday.