As two potentially major hurricanes are brewing in the Atlantic Ocean, investors bid up shares that stand to benefit from increased sales of plywood and generators and sold shares that would be hurt by damage claims.

Hurricane Florence could strike a direct blow on the southeast U.S. later this week. Florence strengthened to a Category 4 storm on Monday morning, according to the National Hurricane Center.

Home Depot and Lowe's shares each rose nearly 2 percent in trading Monday, while generator manufacturer Generac stock popped 5.7 percent and roofing supplier Beacon rose 7.3 percent. Generac hit a 4½ high in trading.

Regional construction companies Louisiana-Pacific and Fluor shares also both rose about 1 percent.

Insurance stocks sank as Florence rolled closer, with Travelers and Allstate each falling by about 2 percent and high-end real estate insurer Chubb falling 0.8 percent.

Far behind Florence is Hurricane Isaac, which was centered about 1,150 miles east of the Windward Islands and moving west. The hurricane center says Isaac is a very small hurricane and its intensity could fluctuate as it approaches the Caribbean