Jim Cramer wrote about multiple expansion in his Real Money column Wednesday morning.
"When you see a stock levitate, that's often pure multiple expansion," said Cramer.
"I don't trust multiple expansion, not that I am necessarily drawn to multiple contraction, lest I stumble on a value trip, although I think CVS's merger with Aetna doesn't produce a black hole as much as a rebirth," Cramer wrote.
Watch for stocks that are moving with reason, he said. For example, Nike (NKE) - Get Report is up because Adidas (ADDYY) is down. United Technology (UTX) - Get Report was up Wednesday morning when Boeing (BA) - Get Report was up.
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