Tuesday brought us the biggest one-day percentage gain for the S&P since May 2002. So how could there be a downside to stocks going up? What made Apple (Nasdaq: AAPL) such a bargain six years ago? Why did high-flying New York Times (NYSE: NYT) fall back to Earth? And how can you find the next great bargain stock? Motley Fool senior analyst Tim Hanson weighs in with some advice from Berkshire Hathaway (NYSE: BRK-B) Vice Chairman Charlie Munger.

Apple is a Motley Fool Stock Advisor recommendation. The Motley Fool owns shares of Berkshire Hathaway, which is a recommendation of both Inside Value and Stock Advisor. Microsoft and Coca-Cola are Inside Value recommendations. Chris owns none of the shares discussed. Tim owns shares of Berkshire Hathaway. The Motley Fool has a disclosure policy.