The Dow in early April had dropped 16% from its previous December peak. The blue-chip index was on track for its worst April decline since 1932 before Trump paused his initial “Liberation Day” tariffs, swiftly lifting stocks out of their slump.

The market is open. The Dow (+0.24%) remains the sole index in the green on the day. In fact, it's towing closer and closer to an all-time high, thanks to one (not so) mystery stock. For the moment, the S&P 500 (-0.