Bitcoin tumbles below $50,000 as caution about rally takes hold

Bitcoin slid Tuesday after a bout of volatility highlighted lingering doubts about the durability of the token’s mesmerizing rally.

The cryptocurrency fell as much as 11% to below $50,000. At one point Monday the digital currency plunged 17% before paring the worst of the slide. It’s still up some 400% in the past year, a rise that dwarfs other assets.

Treasury Secretary Janet Yellen and Microsoft Corp. co-founder Bill Gates were the latest to weigh into a debate over the digital coin. Gates cautioned about how investors can be swept up in manias, while Yellen said Bitcoin is an “extremely inefficient way of conducting transactions.”