Most investors have never heard of Ashton "Ash" Carter. But the man who is the Pentagon's de facto operations chief retires next week, and his departure could have a major impact on the defense industry and Wall Street.
Carter will retire on Dec. 4, after four and a half years at the DoD, first as the Pentagon's chief weapons buyer and then as deputy secretary of defense.
While at the department, Carter made his mark by, among other things, staunchly opposing consolidation among the Pentagon's largest contractors—the so-called "Primes": Boeing, Lockheed Martin, Northrop-Grumman, Raytheon, and General Dynamics.
Some experts have already begun speculating that Carter's departure, coupled with further mandatory spending cuts known as sequestration coming in January, could lead to an uptick in merger and acquisition activity among defense companies.
(Watch: Pentagon hits major milestone)
"I don't think very many people in the Department of Defense care about further concentration in the Defense industry, but Ash Carter put a stake in the ground at a time before defense demand softened," Loren Thompson, a defense analyst at the Lexington Institute, said in an interview.