 Posner was born on January 11, 1943, in Baltimore and joined his father's business acquiring and managing corporations.In 1988, the SEC charged that the Posners had colluded with Ivan Boesky and Michael Milken to conceal their stock purchases during the 1984 Posner-led takeover of the Fischbach Corporation.While Boesky and Milken agreed to plead guilty to felony counts in relation to their activities in the Fischbach case, the Posners were required to relinquish the financial gains they had made in the deal and to relinquish ownership stakes they held in other companies.