Bitcoin Can’t Keep It Chill

This was looking like the year that bitcoin would finally move beyond its sketchy reputation as an anonymous way to buy drugs and stolen credit cards. Banks had started to study how they could use the six-year-old digital currency to update the world’s outdated money transfer mechanisms; and its price swings were becoming less extreme, making it less risky for ordinary folks to use.

Then bitcoin’s price inexplicably spiked 98 percent in three weeks, touching $502 on Nov. 4, before dropping 20 percent the next day. That’s the kind of unruly fluctuation you might expect in a penny stock, not an invention that’s been hyped as a trustworthy replacement for unreliable government-issued money.