Tom Gayner acquired 749k Marsh & McLennan Cos. shares worth $154M. That's 1.28% of their equity portfolio (24th largest holding). The first Marsh & McLennan Cos. trade was made in Q4 2007. Since then Tom Gayner bought shares 21 more times and sold shares on five occasions. The stake costed the investor $61.5M, netting the investor a gain of 151% so far.