Tesla bought Bitcoin. It feels as if that sentence should properly begin with "Imagine if ...” and a wry chuckle. But no. Imagine no longer.

Tesla Inc.’s annual report disclosed the electric-car maker updated its investment policy last month and then bought $1.5 billion of the crypto. That news added roughly $5,000, or 14%, to said crypto on Monday morning, sending it to a new all-time high. Tesla’s own stock rose about 3%, adding roughly $11 billion in market cap, because — well, probably because of this. I don’t know.

On the face of it, a change in investment policy that simply by its disclosure adds hundreds of millions of dollars in value to a company’s portfolio — and billions to the company’s market cap — in a sort-of virtual virtuous circle seems like a winning change. Ordinarily, such things lie forgotten in the 10-K.