Tom Gayner acquired 685 Thousand Marsh & McLennan Cos. shares worth $141 Million. That's 1.40% of their equity portfolio (23rd largest holding). The first Marsh & McLennan Cos. trade was made in Q4 2007. Since then Tom Gayner bought shares fifteen more times and sold shares on four occasions. The stake costed the investor $47.6 Million, netting the investor a gain of 196% so far.