RealMoney Radio: Bye-Bye, Akamai

The first listener to call Jim Cramer's "RealMoney" radio show Friday wanted to know about Akamai(AKAM Quote).

The caller said she bought the stock in the high-$20s, sold it at $35, and wanted to buy more on this dip. However, Akamai has already started coming up again and she asked if it is too late to buy more.

"The opportunity to buy Akamai has come and gone," Cramer said. The stock was $31 on Wednesday, but now that it's up to $34 he said he would stay away.

In selloffs like this, he said that people should never buy up. Tech stocks have bottomed and so some are lifting off again, he said. However, machinery is now trying to find a bottom, so he would think about looking around in that group. He added that oil and oil services are still in freefall, but that he doesn't mind buying a little there if he believes the company will move higher once it bottoms.

He called Dun & Bradstreet(DNB Quote) "the quintessential company that does well in a slowdown" because people use its product to reduce credit risk.

This stock goes up when the Federal Reserve raises interest rates, he added, which is why it's close to its 52-week high and did not go down in this selloff. He believes the stock is a buy.

He said that UnitedHealth(UNH Quote), which he owns for his charitable trust Action Alerts PLUS, is one of best-performing stocks he has ever seen. This is why he just bought a little more.

A lot of people did things in options that weren't right, and this could cause earnings to be restated, he said, adding that he sees a 12-cent restatement.

But he said that the company has a lot of firepower to buy back stock, and that the worse thing that could happen is that the chief executive, William McGuire, will have to leave and give money back to the company. He said that, for him, it made sense to pick up more of the stock now that it's at a 52-week low and down 27% year-to-date.