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 Real Estate
Industrial REITs0.40%+0.10 ppRetail REITs0.36%+0.09 ppSelf-Storage REITs0.31%+0.08 ppMulti-Family Residential REITs0.33%+0.07 ppTelecom Tower REITs0.85%+0.04 ppReal Estate Services0.12%+0.03 ppOther Specialized REITs0.05%+0.01 ppOffice REITs0.17%+0.01 ppData Center REITs0.40%-0.01 ppTimber REITs0.10%-0.00 ppHealth Care REITs0.25%-0.00 ppHotel & Resort REITs0.04%-0.00 ppSingle-Family Residential REITs0.00%+0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.85%
Industry change · 12M
+0.04 pp
Telecom Tower REITs · contribution
+0.043 pp
Company participation
67%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Dec 2021 · 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 |
|---|---|---|---|---|---|---|---|
| American Tower → AMT | United States | $133.2bn | 0.427% | +0.003 pp | +0.023 pp | +32.9% | No |
| Crown Castle → CCI | United States | $90.2bn | 0.289% | +0.026 pp | +0.011 pp | +35.1% | Yes |
| SBA Communications → SBAC | United States | $42.3bn | 0.136% | +0.008 pp | +0.009 pp | +39.0% | Yes |
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.