Investment guru and mega-billionaire Warren Buffett took a new plunge today: He sent his first message on Twitter — and within a short time had more more than 100,000 followers.

“Warren is in the house,” Buffett said on the microblog service, sparking a fury of re-tweets of the debut words of the savvy investor dubbed the “Oracle of Omaha.”

There was no news, no sage advice on how to manage a stocks portfolio, or announcements of the latest big-money moves of his investment house Berkshire Hathaway.

But perhaps in anticipation, followers to the new account multiplied at a pace faster than 1,000 a minute.

Buffett, the world’s fourth richest person with $ 53.5 billion, according to Forbes, got a quick reply from a fellow super-tycoon — and card-player — long present on Twitter: Microsoft co-founder Bill Gates.

“Welcome to Twitter @WarrenBuffett. First ever Twitter bridge tourney starts now. I bid 3 Hearts,” said Gates.

Buffett made his first tweet during an interview with Fortune at the University of Nebraska Omaha.

“Who says you can’t teach an old dog new tricks?” he joked.