[zevyoura]

According to the article Ballmer has ~$20B. 10% is significant, but not exactly "destroy[ing] the value of his own net worth."

[waterlesscloud]

According to Wikipedia, Ballmer joined Microsoft as employee #30 in 1980.

A year later, in 1981, when Microsoft incorporated, Ballmer held 8% of the shares.

That was a pretty neat trick.

[Omniusaspirer]

My google-fu seems to be failing me, does anyone know how exactly he obtained an 8% stake in the company in a single year?