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
Latest available · not live
20182026
1 · Sector
Weight and 12M allocation change
2 · Industry
Inside Real Estate
Telecom Tower REITs0.20%-0.10 ppReal Estate Services0.08%-0.08 ppRetail REITs0.24%-0.05 ppHealth Care REITs0.37%+0.04 ppMulti-Family Residential REITs0.13%-0.04 ppSelf-Storage REITs0.13%-0.03 ppHotel & Resort REITs0.07%-0.02 ppOffice REITs0.03%-0.02 ppTimber REITs0.02%-0.01 ppSingle-Family Residential REITs0.03%-0.01 ppIndustrial REITs0.20%-0.01 ppOther Specialized REITs0.06%-0.00 ppData Center REITs0.27%-0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.20%
Industry change · 12M
-0.10 pp
Telecom Tower REITs · contribution
-0.102 pp
Company participation
0%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Sep 2026 · 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 | $76.3bn | 0.128% | -0.004 pp | -0.052 pp | -11.4% | No |
| Crown Castle → CCI | United States | $28.4bn | 0.048% | -0.010 pp | -0.036 pp | -27.4% | No |
| SBA Communications → SBAC | United States | $17.0bn | 0.029% | -0.004 pp | -0.013 pp | -15.1% | 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.