Observatory · observe first
Arthur J. Gallagher & Co.
AJG · United States · Insurance Brokers · matched S&P 500 member. Follow its market-weight contribution.
Historical time machine
Historical observation
20182026
Universe weight
0.123%
12M weight contribution
-0.025 pp
3M weight contribution
-0.003 pp
12M price return
-16.7%
Share of matched S&P 500 members
Monthly observations through Jan 2026
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 |
|---|---|---|---|---|---|
| Jan 2026 | $64.0bn | 0.123% | -0.025 pp | -16.7% | No |
| Dec 2025 | $66.5bn | 0.130% | -0.011 pp | -8.0% | No |
| Nov 2025 | $63.6bn | 0.125% | -0.026 pp | -20.1% | No |
| Oct 2025 | $64.0bn | 0.125% | -0.020 pp | -10.6% | No |
| Sep 2025 | $79.4bn | 0.159% | +0.015 pp | +11.0% | No |
| Aug 2025 | $77.6bn | 0.161% | +0.006 pp | +4.3% | No |
| Jul 2025 | $73.6bn | 0.155% | +0.044 pp | +2.1% | No |
| Jun 2025 | $82.0bn | 0.177% | +0.071 pp | +24.4% | No |
| May 2025 | $89.0bn | 0.202% | +0.096 pp | +38.3% | Yes |
| Apr 2025 | $81.7bn | 0.196% | +0.049 pp | +37.8% | Yes |
| Mar 2025 | $87.9bn | 0.209% | +0.058 pp | +39.2% | Yes |
| Feb 2025 | $86.0bn | 0.192% | +0.041 pp | +39.3% | Yes |
| Jan 2025 | $66.2bn | 0.147% | -0.002 pp | +31.2% | Yes |
| Dec 2024 | $62.3bn | 0.141% | -0.004 pp | +27.3% | Yes |
| Nov 2024 | $68.5bn | 0.151% | -0.016 pp | +26.3% | Yes |
| Oct 2024 | $61.7bn | 0.145% | -0.028 pp | +20.5% | Yes |
| Sep 2024 | $61.6bn | 0.144% | -0.021 pp | +24.6% | Yes |
| Aug 2024 | $64.1bn | 0.155% | -0.003 pp | +27.8% | Yes |
| Jul 2024 | $62.1bn | 0.111% | +0.011 pp | +33.2% | No |
| Jun 2024 | $56.7bn | 0.106% | -0.003 pp | +19.2% | No |
| May 2024 | $55.4bn | 0.106% | -0.000 pp | +27.7% | No |
| Apr 2024 | $50.9bn | 0.147% | -0.002 pp | +13.9% | No |
| Mar 2024 | $54.2bn | 0.150% | +0.012 pp | +32.0% | No |
| Feb 2024 | $52.9bn | 0.152% | +0.012 pp | +31.9% | No |
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.