"We don't even know how some of these companies are doing, yet people keep buying them," said Jim Cramer on CNBC's "Stop Trading!" segment on Friday.Research In Motion ( RIMM) "lowered expecations and then beat them," he said. Apple ( AAPL) CEO Steve Jobs "gets sick, and Apple goes up 20 points." "You keep hearing things are bad," said Cramer. "Then you see the stock of Nike ( NKE), which has been climbing since early March. "No one's doing better, but the stocks are saying that they will, and that's very confusing to people," said Cramer. "We're buying first and asking questions later." "We're buying first and asking questions later," Cramer said. As for the president, Cramer said that Obama was getting a failing grade in his first month for dealing with the economic crisis, but recently he's improved to a B+. "He has come on so strong," said Cramer, and the G-20 Summit has been "fantastic" for him.