"We've owned stocks that we've lost money in," Buffett told CNBC's "Squawk Box." "If I'm wrong, you sell them out and take a big loss. We've done that on a few occasions with stocks and bonds over the years."
Shares of IBM have fallen more than 4 percent this year and are off about 18.5 percent in the last year.
"What you pay for a stock doesn't mean anything. What means something is where the company's going to be in five to 10 years," Buffett said. "I think IBM will be worth more money but, like I said, I could be wrong but we'll accept that."