Limestone Fund, LLC -- The close-knit founders of Mountain Group Capital partnered with former Asurion EVP and chief marketing officer Byron Smith to form Limestone. MGC's Joe Cook Jr., Joe Cook III and in-law Steve Singleton aren't traders - they like to buy well-run businesses with revenue up to $30 million, and with management that's willing to stay aboard to ensure continued growth. Cook Jr. is also co-founder and chairman of Ironwood Pharmaceuticals, a former chairman of Amilyn Pharmaceuticals and was a longtime executive with pharmaceutical maker Eli Lilly & Co. Joe Cook III, meanwhile, was a vice president in the investment banking group of J.C. Bradford & Co. Smith picked-up some marketing chops early-on at Procter & Gamble and Pepsico, then began a journey through telecom and broadband with GTE Wireless (Verizon), AT&T and Excite @Home. He earned his bachelor's at MTSU and his MBA at the University of Chicago. He's an adjunct teaching small-business management at Vanderbilt's Owen Graduate School of Management. MGC's sole Tennessee-based portfolio company is Quality Filtration LLC, although another portfolio company, St. Louis-based Clinical Products, manufacturers its goods in Nashville. Contact: (615) 313-9995. ♦