Krispy Kreme Doughnuts Inc. gained the most market value during the second quarter among the 50 companies measured in the Rosenberg Center Franchise 50 Index.

The index was founded in 2000 by William Rosenberg, the founder of Dunkin' Donuts. The franchises in the index represent more than 98 percent of the market capitalization of all U.S. public companies engaged in business franchising. The index overall fell 4.4 percent in the quarter.

Krispy Kreme's first profitable quarter in three years, along with its international sales, gave its market value a 64.7 percent jump during the quarter.

Scott Miracle-Gro Co. had the biggest decline in market value at 45.4 percent. It makes, markets and sells lawn- and garden-care products and services.