Jim Cramer's 'Stop Trading!': Don't Trade on Gustav

"Be careful," Jim Cramer warned viewers on Wednesday's "Stop Trading!" on CNBC. "You need a direct hit in order to take out the Gulf."

Cramer said he's wary about making a trade in the natural gas and oil company group on the belief that Tropical Storm Gustav will hit the Gulf Coast, because if it doesn't hit, oil could be down by $8 to $9 by Tuesday. "I like the group," he said, but it's getting overheated on weather reports.

Addressing a recent story in The Wall Street Journal declaring that the infrastructure trade is done, Cramer said: "If the party's really over, then why is Fluor (FLR Quote - Cramer on FLR - Stock Picks)up so big?" He said Shaw Group (SGR Quote - Cramer on SGR - Stock Picks) and Foster Wheeler(FWLT Quote - Cramer on FWLT - Stock Picks), which he owns for his Action Alerts PLUS charitable trust, are also up.

Next, Cramer said that he wants to know the Treasury source that Barron's used in the article that contributed to the 50% fall in share prices for Freddie Mac (FRE Quote - Cramer on FRE - Stock Picks) and Fannie Mae (FNM Quote - Cramer on FNM - Stock Picks), which have been climbing ever since. "All that's happened is that it's gotten worse for Fannie and Freddie," Cramer said, "but the stocks go up every day. Where is that Barron's source?"

Finally, Cramer turned to Quanta Services (PWR Quote - Cramer on PWR - Stock Picks), which he's been buying for his charitable trust. Quanta has figured out how to address the problem of connecting wind turbines to the grid, Cramer said.