Katy Perry Asks Warren Buffett for Stock Market Advice

Katy Perry didn't need to hear Warren Buffett's roar ... a whisper did just fine.

Katy met Warren at his famous Berkshire Hathaway office in Nebraska. She definitely fangirl'd out, which totally makes sense. Tons of celebs make the pilgrimage to visit the Oracle of Omaha 'cause who doesn't want to meet the billionaire of billionaires?

The video's awesome ... we learn the secret to the Coke machine at Warren's office, and Katy couldn't resist doing what everyone does when they get an audience with Warren.