---
title: How to Compare Institutional Portfolios Using Concentration Metrics
type: learn
slug: compare-institutional-portfolios-concentration-metrics
canonical_url: https://13finsight.com/learn/compare-institutional-portfolios-concentration-metrics
published_at: 2026-04-14T20:50:45.742Z
updated_at: 2026-04-14T20:50:45.743Z
author: Marcus Chen
author_title: Senior Market Analyst
author_url: https://13finsight.com/authors/marcus-chen
word_count: 137
locale: en
source: 13F Insight
---

# How to Compare Institutional Portfolios Using Concentration Metrics

> Not all 13F portfolios carry equal signal. Here is how Top-5 concentration and position count help distinguish conviction stock pickers from index trackers.

Not all institutional portfolios carry equal signal. Some filers hold thousands of positions spread thinly while others concentrate capital in high-conviction bets. Concentration metrics help you distinguish signal from noise on 13F Insight.TL;DRTop-5 and Top-10 ratios reveal how much is in the largest positions.Above 30% top-5 = active stock-picking conviction.Below 15% top-5 = index-tracking or broad-mandate.Position count alone is misleading.Key MetricsMetricWhat It RevealsTop-5 WeightCapital in the biggest betsTop-10 WeightBreadth of convictionPosition CountPortfolio breadth (can mislead)Real Examples (Q4 2025)FilerAUMTop-5PositionsTypeBerkshire Hathaway$274B~70%~40Ultra-concentratedCapital World$735B19.8%574Active pickerDimensional$477B17.9%~15KFactor-basedVanguard$6.9T24.8%17KIndex trackerNorges Bank$935B26.3%1,577Sovereign fundHow to InterpretHigh (>30%): Filers like Berkshire make enormous bets. Each change is a deliberate decision. Moderate (15-30%): Active managers with diversified conviction. Low ( Broad mandates where individual changes carry less signal.Norges Bank holds 1,577 positions across $935B — fewer than filers one-tenth its size. Position count alone tells you nothing about concentration.FAQ

## FAQ

### What is a good Top-5 concentration for signal quality?

Above 25-30% suggests genuine stock picking. Below 15% is likely index-tracking.

### Why does Vanguard show high Top-5 despite being passive?

The top 5 S&P 500 stocks are so large that even market-cap-weighted indexes appear concentrated. This reflects the market, not active picking.

### Should I only follow concentrated filers?

No. Concentrated filers give stronger individual position signals. Diversified filers reveal broader market trends.

### How does WhaleScore relate to concentration?

WhaleScore combines concentration, consistency, and scale into a single quality signal. High WhaleScore often correlates with moderate-to-high concentration.

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Source: 13F Insight — https://13finsight.com/learn/compare-institutional-portfolios-concentration-metrics
Author: Marcus Chen — https://13finsight.com/authors/marcus-chen
Last updated: 2026-04-14T20:50:45.743Z