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 Materials
Paper & Plastic Packaging Products & Materials25.93%+25.58 ppIndustrial Gases0.41%-0.25 ppSpecialty Chemicals0.33%-0.22 ppConstruction Materials0.21%+0.05 ppFertilizers & Agricultural Chemicals0.11%-0.05 ppGold0.16%+0.02 ppMetal, Glass & Plastic Containers0.02%-0.01 ppCommodity Chemicals0.04%-0.01 ppCopper0.11%-0.01 ppSteel0.11%+0.00 pp
3 · Sub-industry
Inside Construction Materials
Construction Materials · weight
0.21%
Industry change · 12M
+0.05 pp
Construction Materials · contribution
+0.052 pp
Company participation
33%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Apr 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 |
|---|---|---|---|---|---|---|---|
| CRH plc → CRH | United States | $79.1bn | 0.107% | -0.050 pp | +0.107 pp | +25.0% | Yes |
| Vulcan Materials Company → VMC | United States | $39.2bn | 0.053% | -0.023 pp | -0.030 pp | +15.8% | No |
| Martin Marietta Materials → MLM | United States | $37.2bn | 0.050% | -0.025 pp | -0.025 pp | +18.8% | 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.