There's been a lot of commotion at the top of the ProSales 100 list, as five of the Top 10 businesses have either made some type of leadership change or bought out a competitor.

No. 1 / ABC Supply The Beloit, Wis.-based company purchased former ProSales 100 No. 4 Bradco Supply in June. That move vaulted ABC Supply from the No. 2 spot over ProBuild and into the top spot on the list.

No. 2 / ProBuild Holdings Bill Myrick became CEO in August, replacing Paul Hylbert, who had led the Denver-based company since 2007.

No. 3 / Beacon Roofing Supply Beacon promoted president and COO Paul Isabella to president and CEO in early December. The Peabody, Mass.-based roofing distributor announced Isabella was succeeding current chairman and CEO Robert R. Buck, who will stay on as chairman.

No. 4 / Stock Building Supply Named Jeffrey G. Rea as CEO in November after Joe Appelmann resigned. Rea came to the Raleigh, N.C.-based company after working for Tyco and Johns Manville. Appelmann departed after guiding the company through a Chapter 11 bankruptcy restructuring, but was unable to get the LBM giant out of the red.

No. 5 / 84 Lumber The lumber giant promoted Frank Cicero to COO in October, filling an open spot.

No. 8 / BMC When we listed it in the ProSales 100, it was BMC Select, but since then it has dropped the "Select" and now is just BMC. The Boise, Idaho-based distributor went through a position swap at the top in July as Peter C. Alexander was named CEO and took the place of Paul Street, who stepped into the chief administrative officer role. COO Stan Wilson retired.