shares of aon plc aon rose 100 to 32499 thursday on what proved to be an allaround positive trading session for the stock market with the sp 500 index spx rising 133 to 414622 and the dow jones industrial average djia rising 114 to 3402969 this was the stocks third consecutive day of gains aon plc closed 1699 below its 52week high 34198 which the company reached on april 21st trading volume 645420 remained 222717 below its 50day average volume of 868137