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
Telecom Tower REITs0.81%+0.81 ppData Center REITs0.39%+0.39 ppIndustrial REITs0.33%+0.33 ppRetail REITs0.32%+0.32 ppMulti-Family Residential REITs0.31%+0.31 ppSelf-Storage REITs0.26%+0.26 ppHealth Care REITs0.26%+0.26 ppOffice REITs0.16%+0.16 ppReal Estate Services0.11%+0.11 ppTimber REITs0.09%+0.09 ppOther Specialized REITs0.04%+0.04 ppHotel & Resort REITs0.04%+0.04 ppSingle-Family Residential REITs0.00%+0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.81%
Industry change · 12M
+0.81 pp
Telecom Tower REITs · contribution
+0.813 pp
Company participation
33%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Sep 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 | $120.8bn | 0.424% | -0.000 pp | +0.424 pp | +12.0% | No |
| Crown Castle → CCI | United States | $74.9bn | 0.263% | -0.035 pp | +0.263 pp | +7.3% | No |
| SBA Communications → SBAC | United States | $36.2bn | 0.127% | +0.004 pp | +0.127 pp | +4.6% | 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.