At this price, Shopify stock could be a buy for risk-tolerant investors like Cathie Wood. It's a bull-market buy, and as interest rates begin to come down, Shopify stock could rise regardless of its high valuation. But if you don't have the stomach for volatility, it's probably not the best candidate for your portfolio.

Cathie Wood developed a reputation as a prescient stock picker as her flagship fund, the Ark Innovation ETF (NYSEMKT: ARKK) more than doubled in 2020, along with several other of her actively traded exchange-traded funds (ETFs).

Cathie Wood, chief of Ark Investment Management, frequently adjusts her top positions, adding to a holding when the stock falls and selling when it rises. Last week she did some notable buying. This week she was selling,

Tesla's electric vehicle sales are shrinking, but Cathie Wood and Ark Invest say there's a different reason to buy the stock.