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
Universe›Industrials›Rail Transportation›Rail Transportation
Rail Transportation · weight
0.53%
Industry change · 12M
-0.05 pp
Rail Transportation · contribution
-0.047 pp
Company participation
33%
of industry constituents above their 6M weight average

4 · Companies driving this sub-industry

Dec 2025 · sorted by absolute contribution to 12-month change

CompanyCountryMarket capUniverse weight3M contribution12M contribution12M price returnAbove 6M weight average
Union Pacific Corporation →
UNP
United States$137.2bn0.269%-0.012 pp-0.045 pp+3.9%No
CSX Corporation →
CSX
United States$67.5bn0.132%-0.000 pp-0.009 pp+14.1%Yes
Norfolk Southern →
NSC
United States$64.8bn0.127%-0.008 pp+0.006 pp+25.6%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.