Wellington Management's $571B Q4 2025 Filing Hides a Healthcare Conviction Bet Beneath the Mega-Cap Surface

Wellington Management Group filed its Q4 2025 13F showing $570.7 billion across 1,878 unique holdings — essentially flat from $571.3B in Q3. The top six names are the usual mega-cap suspects. But positions #7 and #8 tell a different story: Eli Lilly (LLY) at $14.4B (2.52%) and Merck (MRK) at $9.1B (1.59%). For a fund this size, having two pharma names in the top 8 is a deliberate healthcare conviction bet.

TL;DR

• AUM: $570.7B (Q4 2025), flat from $571.3B (Q3) — less than 0.1% change
• Holdings count: 1,878 unique — mid-range concentration for a $500B+ filer
• Top holding: Nvidia (NVDA) at 4.60%, worth $26.2B
• Healthcare conviction: LLY ($14.4B, 2.52%) + MRK ($9.1B, 1.59%) + UNH ($5.2B, 0.91%) = $28.6B in healthcare in top 12
• Top-5 concentration: 18.4% — moderate for an active manager
• Financials accent: Wells Fargo ($6.7B) and Mastercard ($7.7B) in top 10
• Whale Score: 73.00

The Healthcare Layer: LLY, MRK, UNH

Eli Lilly at $14.4B is Wellington's 7th largest position — the GLP-1/obesity drug thesis that has driven LLY's multi-year run. Merck at $9.1B (86.4M shares) provides a different healthcare exposure: Keytruda-driven oncology revenue. And UnitedHealth Group at $5.2B adds managed care. Together, these three healthcare names account for $28.6B (5.0% of the portfolio).

Compare this to pure index managers like Vanguard or BlackRock, where healthcare weighting mirrors the S&P 500 (~12-13%). Wellington's active overweight in specific pharma names signals genuine sector conviction.

Flat AUM: The Dog That Didn't Bark

Wellington's AUM barely moved: $571.3B to $570.7B, a -0.1% change. In a quarter where most mega-filers grew, this flatline is notable. It suggests either modest net outflows offsetting market gains, or deliberate portfolio de-risking that kept the book from growing with the market.

What Analysts Might Misread

Misread #1: “Flat AUM means Wellington is losing assets”

The $600M decline on a $571B base is noise, not signal. Holdings count barely changed (7,635 to 7,580). This is a steady-state quarter, not a contraction story.

Misread #2: “Two pharma stocks doesn't make a healthcare bet”

At Wellington's scale, $14.4B in LLY alone is a $14.4 billion active decision. Combined with MRK and UNH, that's $28.6B in healthcare — more than many dedicated healthcare funds manage in total AUM.

Frequently Asked Questions

What is Wellington Management's largest holding?

Nvidia at 4.60% ($26.2B), followed by Microsoft at 4.15% ($23.7B) and Apple at 3.68% ($21.0B).

Does Wellington have a healthcare overweight?

Yes. Eli Lilly (#7, $14.4B), Merck (#8, $9.1B), and UnitedHealth (#12, $5.2B) give Wellington $28.6B in healthcare in the top 12 — a notable concentration for a diversified manager.

How big is Wellington Management?

$570.7B in 13F AUM across 1,878 unique holdings as of Q4 2025. Wellington is one of the largest independently owned investment management firms globally.