If you’re only looking at stock price then Ballmer did exceptionally well.
Nah, not really. 2000 was the dot-com bust (which was the start of the death spiral for a lot of formerly high-flyers, including Sun Microsystems) and 2001 was the DoJ consent decree, which brought a lot of MS's attempts to expand to a screeching halt. Ballmer, while being thoroughly mediocre in a lot of ways, deserves at least some credit for not tanking MS in that era.