Jim Cramer Gives His Opinion On Shake Shack, Alder Biopharmaceuticals And CIGNA

On CNBC's Mad Money, Jim Cramer said that Shake Shack Inc (NYSE: SHAK) is overvalued. He added that the stock should have never traded as high as it did and it happened because of a short squeeze.

Alder Biopharmaceuticals Inc (NASDAQ: ALDR) rallied a lot and now it is reversing, said Cramer. He thinks that the best strategy would be to wait for the stock to trade back to $44.50, the price of its secondary offering, and then buy some.

Cramer explained that CIGNA Corporation (NYSE: CI) is trading lower because traders are concerned that it is going to trade like Humana Inc (NYSE: HUM), which didn't move higher after the takeover announcement. He would be cautious with CIGNA.