The Banker Who Put His Faith in Armstrong – By Andrew Ross Sorkin

When Lance Armstrong’s interview with Oprah Winfrey about his suspected use of illegal performance-enhancing drugs is broadcast on Thursday, an investment banker will most likely be watching it very carefully (and nervously): Thomas Weisel.

Mr. Weisel is a legend in finance and Silicon Valley. He was the banker behind Yahoo’s public offering and some of the biggest deals during the dot-com bubble. He famously sold the firm he ran, Montgomery Securities, for $1.2 billion in 1997. And he sold his next firm, Thomas Weisel Partners, for $300 million to Stifel Financial in 2010.

But it is Mr. Weisel’s extracurricular activity that connects him to the news of the moment: he was Mr. Armstrong’s biggest financial backer and the single individual most responsible for the money machine that propelled Mr. Armstrong’s career.