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 · Sep 2021Market-cap weights, not measured fund flows · pp = percentage points
Gaining weight
114
industries · over the last 12 months
Losing weight
1
industries · over the last 12 months
Accelerating
0
positive 3M gains are speeding up
Slowing
59
3M movement is easing, in either direction

Gaining market weight

Largest sector gains · last 12 months

Losing market weight

Largest sector declines · last 12 months

The pace is changing

Latest 3 months versus the previous 3 months

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.

Apple Inc.+8.210 pp
All other companies+0.358 pp
33% of companies above their 6M weight average
See what contributed →
Concentrated

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

Arthur J. Gallagher & Co.-99.792 pp
All other companies+0.550 pp
100% 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
Insurance Brokers
Gained weight for 3 consecutive months
0.66%-99.24 ppSlowingConcentrated
Technology Hardware, Storage & Peripherals
Lost weight for 1 consecutive month
8.57%+8.57 ppSlowingConcentrated
Systems Software
Lost weight for 1 consecutive month
7.61%+7.60 ppSlowingConcentrated
Diversified Banks
Gained weight for 2 consecutive months
5.02%+5.01 ppSlowingConcentrated
Pharmaceuticals
Lost weight for 2 consecutive months
4.62%+4.62 ppReversing downwardBroad
Aerospace & Defense
Gained weight for 1 consecutive month
4.02%+4.02 ppReversing downwardConcentrated
Application Software
Lost weight for 1 consecutive month
3.96%+3.96 ppSlowingBroad
Semiconductors
Gained weight for 2 consecutive months
3.51%+3.51 ppReversing downwardBroad
Health Care Equipment
Lost weight for 2 consecutive months
3.09%+3.08 ppReversing downwardBroad
Biotechnology
Lost weight for 1 consecutive month
2.51%+2.51 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.