Observatory · observe first
Follow the allocation change
Matched S&P 500 members → sector → industry → sub-industry → company. Each step uses the same percentage points.
Historical time machine
Historical observation
20182026
1 · Sector
Weight and 12M allocation change
2 · Industry
Inside Industrials
Aerospace & Defense2.70%+0.50 ppConstruction Machinery & Heavy Transportation Equipment0.94%+0.22 ppConstruction & Engineering0.30%+0.17 ppHeavy Electrical Equipment0.39%+0.15 ppHuman Resource & Employment Services0.26%-0.13 ppIndustrial Machinery & Supplies & Components0.95%-0.11 ppDiversified Support Services0.27%-0.08 ppRail Transportation0.53%-0.08 ppResearch & Consulting Services0.11%-0.06 ppEnvironmental & Facilities Services0.40%-0.05 ppIndustrial Conglomerates0.55%-0.04 ppBuilding Products0.51%-0.04 ppTrading Companies & Distributors0.19%+0.03 ppPassenger Airlines0.19%-0.02 ppCargo Ground Transportation0.11%-0.02 ppData Processing & Outsourced Services0.04%-0.02 ppAgricultural & Farm Machinery0.27%-0.01 ppAir Freight & Logistics0.35%-0.01 ppElectrical Components & Equipment0.61%-0.01 ppPassenger Ground Transportation0.32%+0.01 pp
3 · Sub-industry
Inside Rail Transportation
Rail Transportation · weight
0.53%
Industry change · 12M
-0.08 pp
Rail Transportation · contribution
-0.077 pp
Company participation
33%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Jan 2026 · sorted by absolute contribution to 12-month change
| Company | Country | Market cap | Universe weight | 3M contribution | 12M contribution | 12M price return | Above 6M weight average |
|---|---|---|---|---|---|---|---|
| Union Pacific Corporation → UNP | United States | $139.5bn | 0.267% | +0.011 pp | -0.067 pp | -2.9% | No |
| CSX Corporation → CSX | United States | $70.3bn | 0.135% | +0.003 pp | -0.006 pp | +16.7% | Yes |
| Norfolk Southern → NSC | United States | $65.4bn | 0.125% | +0.000 pp | -0.003 pp | +16.5% | No |
Company contributions use weights among matched S&P 500 members and add through each level without rescaling. Companies without matched shares and prices are omitted. These observations do not establish official index weights or actual fund flows.