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 REITs0.68%-0.17 ppHotel & Resort REITs0.15%+0.11 ppReal Estate Services0.20%+0.08 ppData Center REITs0.32%-0.08 ppSingle-Family Residential REITs0.07%+0.07 ppSelf-Storage REITs0.25%-0.06 ppOffice REITs0.12%-0.04 ppMulti-Family Residential REITs0.28%-0.04 ppIndustrial REITs0.38%-0.02 ppHealth Care REITs0.23%-0.02 ppRetail REITs0.38%+0.02 ppTimber REITs0.08%-0.02 ppOther Specialized REITs0.05%+0.00 pp
3 · Sub-industry
Inside Other Specialized REITs
Other Specialized REITs · weight
0.05%
Industry change · 12M
+0.00 pp
Other Specialized REITs · contribution
+0.004 pp
Company participation
100%
of industry constituents above their 6M weight average
4 · Companies driving this sub-industry
Dec 2022 · 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 |
|---|---|---|---|---|---|---|---|
| Iron Mountain → IRM | United States | $14.5bn | 0.052% | +0.002 pp | +0.004 pp | -0.1% | 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.