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 REITs0.31%-0.02 ppHealth Care REITs0.28%-0.02 ppSelf-Storage REITs0.27%+0.01 ppMulti-Family Residential REITs0.33%-0.01 ppTelecom Tower REITs0.75%+0.01 ppRetail REITs0.49%-0.01 ppReal Estate Services0.10%+0.01 ppHotel & Resort REITs0.08%-0.01 ppIndustrial REITs0.19%-0.00 ppTimber REITs0.16%-0.00 ppOther Specialized REITs0.05%+0.00 ppOffice REITs0.18%-0.00 ppSingle-Family Residential REITs0.00%+0.00 pp
3 · Sub-industry
Inside Telecom Tower REITs
Telecom Tower REITs · weight
0.75%
Industry change · 12M
+0.01 pp
Telecom Tower REITs · contribution
+0.008 pp
Company participation
67%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Feb 2018 · 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 | $44.8bn | 0.268% | +0.007 pp | +0.007 pp | -2.4% | Yes |
| American Tower → AMT | United States | $61.4bn | 0.368% | +0.007 pp | +0.007 pp | -5.7% | Yes |
| SBA Communications → SBAC | United States | $18.5bn | 0.111% | -0.006 pp | -0.006 pp | -9.9% | 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.