Aon Plc
A global professional services firm that helps organizations manage risk and take care of their people, Aon brokers insurance, advises on retirement and health benefits, and consults on talent. It was born in 1982 in Chicago from the merger of Ryan Insurance Group and Combined International Corporation, and its name comes from a Gaelic word meaning "one" — adopted in 1987 to signal a unified identity. Aon serves clients in more than a hundred countries.
Estimated from filings — the split-adjusted price range over the quarters each manager built the position. A range, not a fill price; 13F reports a quarter-end snapshot, not a trade date.