Observatory · observe first
Aon plc
AON · United States · Insurance Brokers · matched S&P 500 member. Follow its market-weight contribution.
Historical time machine
Historical observation
20182026
Universe weight
0.205%
12M weight contribution
+0.021 pp
3M weight contribution
+0.029 pp
12M price return
+20.6%
Share of matched S&P 500 members
Monthly observations through Mar 2025
Company price index
A separate dimension from market allocation
Historical observations
Most recent 24 observations at or before the selected month
| Month | Market cap | Universe weight | 12M weight change | 12M return | Above 6M weight average |
|---|---|---|---|---|---|
| Mar 2025 | $86.2bn | 0.205% | +0.021 pp | +20.6% | Yes |
| Feb 2025 | $88.4bn | 0.198% | +0.018 pp | +30.5% | Yes |
| Jan 2025 | $80.2bn | 0.178% | +0.001 pp | +25.0% | No |
| Dec 2024 | $77.7bn | 0.176% | +0.002 pp | +24.5% | Yes |
| Nov 2024 | $84.7bn | 0.187% | -0.018 pp | +20.2% | Yes |
| Oct 2024 | $79.3bn | 0.186% | -0.024 pp | +19.4% | Yes |
| Sep 2024 | $75.2bn | 0.175% | -0.045 pp | +7.6% | Yes |
| Aug 2024 | $74.7bn | 0.180% | -0.035 pp | +4.0% | Yes |
| Jul 2024 | $71.4bn | 0.128% | -0.013 pp | +3.8% | No |
| Jun 2024 | $63.8bn | 0.120% | -0.043 pp | -14.2% | No |
| May 2024 | $61.2bn | 0.117% | -0.038 pp | -7.9% | No |
| Apr 2024 | $61.3bn | 0.178% | -0.047 pp | -12.5% | No |
| Mar 2024 | $66.2bn | 0.184% | -0.037 pp | +6.7% | No |
| Feb 2024 | $62.7bn | 0.180% | -0.040 pp | +4.7% | No |
| Jan 2024 | $59.8bn | 0.178% | -0.048 pp | -5.6% | No |
| Dec 2023 | $58.3bn | 0.174% | -0.050 pp | -2.3% | No |
| Nov 2023 | $65.8bn | 0.205% | -0.011 pp | +7.4% | Yes |
| Oct 2023 | $61.9bn | 0.211% | +0.004 pp | +10.7% | Yes |
| Sep 2023 | $65.8bn | 0.220% | -0.002 pp | +21.9% | Yes |
| Aug 2023 | $67.6bn | 0.216% | +0.005 pp | +20.3% | Yes |
| Jul 2023 | $64.6bn | 0.141% | -0.070 pp | +10.3% | No |
| Jun 2023 | $70.5bn | 0.163% | -0.060 pp | +29.0% | No |
| May 2023 | $63.0bn | 0.156% | -0.055 pp | +12.7% | No |
| Apr 2023 | $66.4bn | 0.224% | +0.003 pp | +13.8% | Yes |
Its weight is estimated market cap divided by the total estimated market cap of matched S&P 500 members for the month. This is not an official float-adjusted S&P index weight.