---
title: "PRIMECAP's $132.11B Q4 Setup: Healthcare-Semiconductor Barbell Gets Heavier"
type: research
slug: primecap-q4-2025-132b-healthcare-semiconductor-barbell
canonical_url: https://13finsight.com/research/primecap-q4-2025-132b-healthcare-semiconductor-barbell
published_at: 2026-03-22T17:13:29.330Z
updated_at: 2026-03-23T07:00:05.089Z
author: Marcus Chen
author_title: Senior Market Analyst
author_url: https://13finsight.com/authors/marcus-chen
word_count: 396
locale: en
source: 13F Insight
---

# PRIMECAP's $132.11B Q4 Setup: Healthcare-Semiconductor Barbell Gets Heavier

> PRIMECAP reported $132.11B in Q4 2025 with Eli Lilly and Micron alone at 12.9% combined, signaling a barbell between healthcare defensiveness and semiconductor cyclicality.

PRIMECAP’s Q4 2025 filing highlights a clear two-engine thesis: healthcare quality plus semiconductor upside. The firm ended the quarter at $132.11B with 319 positions, led by Eli Lilly (LLY) at $9.96B and Micron (MU) at $7.08B. TL;DR Canonical AUM: $132.11B in 2025Q4. Top pair concentration: LLY (7.54%) + MU (5.36%) = 12.90% combined. Overall concentration: Top-1 7.5%, top-5 21.8%, top-10 33.4%. Largest names after top two: GOOGL ($4.74B), MSFT ($3.52B), KLAC ($3.49B). AUM trend: Recovered from $120.96B in ’25 Q1 to $132.11B in ’25 Q4. Read-through: PRIMECAP looks like it is adding cyclical growth participation without abandoning quality anchors. Filing Snapshot Manager: PRIMECAP Management Co/CA/Quarter: 2025Q4Canonical AUM: $132.11BPositions: 319WhaleScore: 72.25 The top book expresses a healthcare + semis barbell PRIMECAP’s lead position in LLY is a classic quality-growth healthcare anchor. The second-largest line, MU, adds a more cyclical semiconductor beta profile. The next group—GOOGL, MSFT, and KLAC—keeps the portfolio tilted toward large-cap platform and chip-cycle exposure. As with other large 13F extracts, the raw “NEW position” labels in API outputs are not treated here as confirmed initiations; they can be artifacts without full filing-to-filing reconciliation. AUM recovery is steady, not explosive The AUM path shows drawdown and repair: $138.13B in ’24 Q2 down to $120.96B in ’25 Q1, then back up through $126.19B (’25 Q2), $130.57B (’25 Q3), and $132.11B (’25 Q4). This is consistent with deliberate re-risking rather than a one-quarter chase. Why this filing matters PRIMECAP remains one of the cleaner examples of concentration with control: meaningful conviction in the top book, but still enough diversification across 319 positions to avoid single-theme fragility. For investors tracking institutional style persistence, this is a strong continuity signal. Related research Baillie Gifford’s growth drawdown quarter D. E. Shaw’s diversification-at-scale profile CalPERS’ core-satellite architecture Q&A What was PRIMECAP’s 13F AUM in Q4 2025? PRIMECAP reported a canonical 13F AUM of $132.11B in 2025Q4. What are PRIMECAP’s largest disclosed holdings? The top disclosed positions are LLY ($9.96B), MU ($7.08B), GOOGL ($4.74B), MSFT ($3.52B), and KLAC ($3.49B). How concentrated is the portfolio? Top-5 concentration is 21.8% and top-10 concentration is 33.4%. Did PRIMECAP recover from its 2025Q1 drawdown? Yes. AUM rose from $120.96B in 2025Q1 to $132.11B in 2025Q4. Can I read “NEW position” markers as true new buys? Not on their own. For large filers, these markers can be extraction artifacts and should be validated using dedicated position-change comparisons.

## FAQ

### What was PRIMECAP's 13F AUM in Q4 2025?

PRIMECAP reported $132.11B in canonical 13F assets for 2025Q4.

### Which holdings were largest in PRIMECAP's Q4 2025 filing?

The largest disclosed holdings were LLY ($9.96B), MU ($7.08B), GOOGL ($4.74B), MSFT ($3.52B), and KLAC ($3.49B).

### How concentrated was PRIMECAP in Q4 2025?

Top-1 concentration was 7.5%, top-5 was 21.8%, and top-10 was 33.4%.

### What does the AUM trend suggest for PRIMECAP?

It suggests a steady recovery: from $120.96B in 2025Q1 to $132.11B in 2025Q4.

### Are 'NEW position' labels reliable proof of fresh buys in this extract?

Not necessarily. For large-filer datasets they can be artifacts and should be validated with quarter-over-quarter position change analysis.

---

Source: 13F Insight — https://13finsight.com/research/primecap-q4-2025-132b-healthcare-semiconductor-barbell
Author: Marcus Chen — https://13finsight.com/authors/marcus-chen
Last updated: 2026-03-23T07:00:05.089Z