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 REITs0.82%-0.14 ppData Center REITs0.40%-0.09 ppRetail REITs0.33%+0.08 ppMulti-Family Residential REITs0.32%+0.07 ppReal Estate Services0.12%+0.04 ppSelf-Storage REITs0.28%+0.02 ppOffice REITs0.16%+0.01 ppIndustrial REITs0.36%+0.01 ppOther Specialized REITs0.04%+0.01 ppTimber REITs0.09%-0.01 ppHotel & Resort REITs0.04%+0.01 ppHealth Care REITs0.25%+0.00 ppSingle-Family Residential REITs0.00%+0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.82%
Industry change · 12M
-0.14 pp
Telecom Tower REITs · contribution
-0.140 pp
Company participation
67%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Oct 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 |
|---|---|---|---|---|---|---|---|
| Crown Castle → CCI | United States | $77.9bn | 0.260% | -0.026 pp | -0.059 pp | +19.0% | No |
| American Tower → AMT | United States | $128.4bn | 0.429% | -0.012 pp | -0.054 pp | +25.3% | Yes |
| SBA Communications → SBAC | United States | $37.8bn | 0.126% | -0.001 pp | -0.028 pp | +19.8% | 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.