A few weeks ago, Space Exploration Technologies (NASDAQ: SPCX) was the most hyped stock on the market. Now it has quietly slipped below its $135 offering price, trading around $124 and down roughly 45% from its post-debut high near $226. For most investors, that kind of round trip is a warning. For contrarians, who like to buy what everyone else is fleeing, it is an invitation to take a closer look.

The slide has more to do with the mechanics of hype than with anything broken inside the business. SpaceX popped on its debut, then got swept into a major stock index, which forced index funds to buy the shares. Once that mechanical demand was satisfied, the buying dried up, momentum reversed, and the stock drifted back…