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 · Apr 2020Market-cap weights, not measured fund flows · pp = percentage points
Gaining weight
45
industries · over the last 12 months
Losing weight
63
industries · over the last 12 months
Accelerating
15
positive 3M gains are speeding up
Slowing
7
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.

Microsoft+2.030 pp
All other companies+0.063 pp
100% of companies above their 6M weight average
See what contributed →
Concentrated

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

Wells Fargo-0.561 pp
All other companies-1.446 pp
100% of companies above their 6M weight average
See what contributed →
Concentrated

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

Bristol Myers Squibb+0.345 pp
All other companies+0.274 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
Systems Software
Gained weight for 2 consecutive months
7.77%+2.09 ppAcceleratingConcentrated
Diversified Banks
Gained weight for 1 consecutive month
4.91%-2.01 ppDeclining fasterConcentrated
Aerospace & Defense
Gained weight for 1 consecutive month
4.00%-1.54 ppReversing downwardConcentrated
Movies & Entertainment
Gained weight for 2 consecutive months
1.25%+1.16 ppReversing downwardConcentrated
Transaction & Payment Processing Services
Gained weight for 2 consecutive months
2.78%+0.72 ppSlowingConcentrated
Pharmaceuticals
Gained weight for 2 consecutive months
6.36%+0.62 ppAcceleratingConcentrated
Biotechnology
Gained weight for 2 consecutive months
3.09%+0.60 ppReversing upwardConcentrated
Oil & Gas Exploration & Production
Gained weight for 1 consecutive month
0.56%-0.57 ppReversing downwardConcentrated
Managed Health Care
Gained weight for 2 consecutive months
2.45%+0.51 ppAcceleratingConcentrated
Wireless Telecommunication Services
Gained weight for 2 consecutive months
0.42%+0.42 ppReversing upwardConcentrated
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.