Observatory · observe first

Where is market allocation moving?

See what is gaining weight, how quickly it is changing, and what is driving the move.

Historical time machine
Historical observation
20182026
S&P 500 matched members · 122 industries · Jan 2026Market-cap weights, not measured fund flows · pp = percentage points
Gaining weight
38
industries · over the last 12 months
Losing weight
77
industries · over the last 12 months
Accelerating
10
positive 3M gains are speeding up
Slowing
23
3M movement is easing, in either direction

What is driving the change?

12-month company attribution · a rising industry does not mean every company is gaining

Follow the hierarchy →
Concentrated

Most of this industry's gains came from a few companies.

Nvidia+2.348 pp
All other companies+1.909 pp
64% of companies above their 6M weight average
See what contributed →
Broad

The loss is shared across much of the industry.

Salesforce-0.347 pp
All other companies-0.681 pp
0% of companies above their 6M weight average
See what contributed →
Concentrated

Most of this industry's gains came from a few companies.

Johnson & Johnson+0.233 pp
All other companies-0.034 pp
86% of companies above their 6M weight average
See what contributed →

Industry movements at a glance

Largest absolute allocation changes · descriptive observations, not rankings of investment merit

Watch the historical rotation →
IndustryMarket weight12M changeMovementParticipationWeight history · 24M
Semiconductors
Gained weight for 2 consecutive months
15.34%+4.26 ppReversing downwardConcentrated
Application Software
Lost weight for 1 consecutive month
2.45%-1.03 ppDeclining fasterBroad
Managed Health Care
Lost weight for 1 consecutive month
0.73%-0.73 ppReversing downwardConcentrated
Broadline Retail
Gained weight for 1 consecutive month
4.97%-0.66 ppDeclining fasterConcentrated
Semiconductor Materials & Equipment
Gained weight for 5 consecutive months
1.19%+0.57 ppAcceleratingConcentrated
Movies & Entertainment
Gained weight for 2 consecutive months
1.15%+0.53 ppReversing upwardConcentrated
Systems Software
Lost weight for 6 consecutive months
6.78%-0.52 ppDeclining fasterConcentrated
Aerospace & Defense
Gained weight for 2 consecutive months
2.70%+0.50 ppReversing upwardBroad
Transaction & Payment Processing Services
Lost weight for 1 consecutive month
0.73%-0.50 ppSlowingConcentrated
Health Care Equipment
Lost weight for 2 consecutive months
2.13%-0.49 ppSlowingBroad
How are these descriptive states defined?

Gaining / losing: 12-month weight change above +0.005pp / below −0.005pp. Direction and speed are separate dimensions, not mutually exclusive recommendations.

Accelerating / slowing: compare the most recent 3M change with the preceding 3M change. Accelerating means a positive change speeds up by >0.02pp. Slowing means the magnitude of movement declines by >0.02pp. A falling industry can also slow.

Reversing: the last two 3M changes have opposite signs, outside a ±0.005pp tolerance. Persistence counts consecutive same-direction monthly changes.

Broad / concentrated: company attribution, not a market-cap concentration shortcut. Concentrated means the three largest same-direction contributors account for ≥70% of gross same-direction changes; otherwise broad requires ≥60% of constituents moving with the industry. Other cases are mixed.

Weights use matched S&P 500 members with SEC-reported shares and monthly prices. Companies without both data series are omitted; weights are normalised across matched members each month. These are simple market-cap estimates, not official float-adjusted S&P weights or measured investor flows.