. >> john mcafee, a mathematician by training knows about risk. in the late '80's he developed the antivirus software that's probably on your computer. he pioneered instant messaging and in both cases he grew bored an cashed out. at your peak, what were you worth? >> i'm not sure. that's the honest truth. i mean, you eventually have enough resources that a tiny fluctuation in the market can make you worth $10 million more in the morning and $10 million less in the evening. >> it's been reported you were worth about $100 million. >> may have been true. >> ballpark? >> may have been, yes. probably. >> probably. >> like many wealthy americans, mcafee got walloped in the simultaneous collapse of real estate and wall street. but he got whacked more than most. since much of his fortune was tied up in luxury properties. >> oddly enough, when real estate markets crash it's the higher end properties that crash the most. simply because they're not necessities. >> at one point you're in the $100 million ballpark and now -- >> less than ten. >> less than $1mi