SAN FRANCISCO—A steep downturn in heavyweight Chinese internet stocks and recent weakness in half of the so-called FANG group have some investors worried that a key component of Wall Street’s near-decade-long rally may be low on fuel.
Outstanding gains in Facebook, Amazon, Netflix, and Alphabet have underpinned much of the U.S. stock market’s rally in recent years, along with the broader tech sector, but the group is widely viewed as overbought and valuations remain expensive.
