Jim Cramer's Stop Trading! Buy Comcast

Comcast (CMCSA Quote) has "a real growth story" that makes the stock a buy despite Thursday's selloff, Jim Cramer said on CNBC's "Stop Trading!" segment.

Cramer shrugged off the 4% drop in the stock, saying Wall Street is worried about the company's plan to spend more in coming years. But Cramer said he expects CEO Brian Roberts' investments in network expansion and customer acquisition to yield a rate of return "better than buying back stock," the universally praised alternative use of capital.

Cramer was less effusive about Under Armour (UA Quote), which is down 7% off Thursday morning's disappointing guidance. Cramer said he still likes the company but allowed that it trades at a superpremium multiple. As a result, Cramer said, "people are going to freak out" when management doesn't boost its earnings outlook at every turn. Cramer said he would look to buy the stock at $43 or $44, against $47 and change Thursday.

Cramer remains bullish on Google (GOOG Quote) but said the Net giant, like Under Armour, "isn't done going down" off Wednesday's numbers. Cramer said investors are disappointed because the company is no longer showing accelerating revenue growth, but he said it could still get to $600 from Thursday afternoon's $488 -- though perhaps with a stop at $450 in between.