Bitcoin isn’t exactly your classic value investment. It’s one of the most volatile assets in the world, and it doesn’t have much of a “book” value – unlike a company that owns physical assets, Bitcoin can’t sell its headquarters if things get rough. There is, of course, no Bitcoin headquarters.

But Murray Stahl, a longtime value investor who now manages $5.5 billion at his New York-based investment firm Horizon Kinetics, considers Bitcoin “the ultimate value investment.” His original $7 million investment from two years ago...