Tom Gayner acquired 764k Marsh & McLennan Cos. shares worth $139M. That's 0.76% of their equity portfolio (28th largest holding). The first Marsh & McLennan Cos. trade was made in Q4 2007. Since then Tom Gayner bought shares 24 more times and sold shares on five occasions. The stake costed the investor $64.3M, netting the investor a gain of 117% so far.