13F Insight
DOSSIER · 13F-HR · Q2 2026

New Mountain Capital, L.L.C.

$139M in tracked AUM across 1 positions as of Q2 2026.

NM
CIK 0001407718 · last filed Jun 30, 2026
Total AUM
$139M
as of Q2 2026
Holdings
1
—
positions
Whale Score
76
76
strong
Activity
—
no data
changes this Q
AI Analysis · Q2 2026

Portfolio Overview

New Mountain Capital, L.L.C. presents a highly concentrated portfolio structure as of the reporting period ended September 30, 2025. The firm reports a total portfolio value of approximately $174.72 million, a decrease of 7.3% from the $188.44 million reported in the previous quarter. The most striking feature of this filing is the extreme lack of diversification; the entire portfolio consists of a single holding. With a total count of just one position, the portfolio has...

Key Holdings

The sole holding in the portfolio is Avantor, Inc. (AVTR), representing 100% of the total assets. The position consists of 14.00 million shares valued at $174.72 million. Avantor is a global provider of mission-critical products and services to the life sciences and advanced technology sectors. For New Mountain Capital, this is not merely a top holding but the exclusive focus of their reported 13F exposure. The stability in the share count (14.00 million shares) suggests that the firm is maintaining a static position and is neither actively trading around the core position nor deploying capital into new opportunities within this specific reporting scope.

Analysis generated by 13F Insight from SEC Form 13F filing data · Q2 2026. Methodology

Quarter at a glance — Q2 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q2 2026.

#HoldingValueSharesWeight
01
AVTR
AVANTOR INC
$139M14.0M100.0%

Filing history

2026Q2Jun 30
$139M▲ 26.3%
1 positionsView →2026Q1Mar 31
$110M▼ 31.6%
1 positionsView →2025Q4Dec 31
$160M▼ 8.2%
1 positionsView →2025Q3Sep 30
$175M▼ 7.3%
1 positionsView →2025Q2Jun 30
$188M▼ 17.0%
1 positionsLocked2025Q1Mar 31
$227M▼ 23.1%
1 positionsLocked2024Q4Dec 31
$295M▼ 82.7%
1 positionsLocked2024Q3Sep 30
$1.7B▲ 14.7%
2 positionsLocked2024Q2Jun 30
$1.5B▼ 5.3%
2 positionsLocked2024Q1Mar 31
$1.6B▲ 7.4%
2 positionsLocked2023Q4Dec 31
$1.5B▼ 20.4%
3 positionsLocked2023Q3Sep 30
$1.8B▼ 15.9%
3 positionsLocked
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