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
Retail REITs0.27%-0.20 ppMulti-Family Residential REITs0.26%-0.13 ppTelecom Tower REITs0.81%-0.11 ppHealth Care REITs0.25%-0.10 ppData Center REITs0.42%+0.05 ppOffice REITs0.16%-0.04 ppSelf-Storage REITs0.22%-0.03 ppHotel & Resort REITs0.04%-0.02 ppIndustrial REITs0.30%+0.02 ppReal Estate Services0.09%-0.02 ppOther Specialized REITs0.03%-0.01 ppTimber REITs0.10%-0.01 ppSingle-Family Residential REITs0.00%+0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.81%
Industry change · 12M
-0.11 pp
Telecom Tower REITs · contribution
-0.114 pp
Company participation
100%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Dec 2020 · 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 | $99.7bn | 0.404% | +0.403 pp | -0.096 pp | -0.5% | Yes |
| Crown Castle → CCI | United States | $68.7bn | 0.278% | +0.278 pp | -0.012 pp | +15.5% | Yes |
| SBA Communications → SBAC | United States | $31.3bn | 0.127% | +0.127 pp | -0.006 pp | +17.8% | 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.