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
Data Center REITs0.25%-0.10 ppHealth Care REITs0.38%+0.10 ppTelecom Tower REITs0.29%-0.09 ppSelf-Storage REITs0.15%-0.06 ppMulti-Family Residential REITs0.16%-0.06 ppRetail REITs0.28%-0.04 ppOffice REITs0.04%-0.03 ppOther Specialized REITs0.05%-0.03 ppTimber REITs0.03%-0.02 ppHotel & Resort REITs0.08%-0.02 ppReal Estate Services0.15%-0.02 ppSingle-Family Residential REITs0.03%-0.01 ppIndustrial REITs0.23%-0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.29%
Industry change · 12M
-0.09 pp
Telecom Tower REITs · contribution
-0.086 pp
Company participation
0%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Nov 2025 · 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 | $84.9bn | 0.167% | -0.031 pp | -0.049 pp | -10.3% | No |
| Crown Castle → CCI | United States | $39.8bn | 0.078% | -0.011 pp | -0.024 pp | -9.3% | No |
| SBA Communications → SBAC | United States | $20.7bn | 0.041% | -0.005 pp | -0.013 pp | -12.4% | 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.