Tesla, the electric-car maker owned by Elon Musk, disclosed in its annual report on Monday that it had purchased $1.5 billion worth of the cryptocurrency. Bitcoin reached a record after Tesla’s announcement, rising more than 10 percent to above $44,000 per coin during early trading on Monday.

The company said the purchase was part of a plan to invest in alternative assets. Mr. Musk has previously encouraged stock frenzies and gotten into trouble for his Twitter pronouncements.

A quirky currency that was intended to be a joke, DogeCoin, has also been swept up in the mania. The digital currency, named for a meme featuring a startled dog, was up 30 percent on Monday — double the gain in Bitcoin.