New Mountain Capital, L.L.C. — 13F Holdings & Portfolio

CIK 1407718 · latest 13F-HR filed 2026-05-13

New Mountain Capital, L.L.C. manages $109.8M in 13F-reported U.S. long-equity assets across 1 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are AVTR (100.00%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 0 new positions, exited 0, added to 0, and trimmed 1.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

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AUM

$109.8M

Long-equity book

Holdings

1

Distinct positions

Period

2026-03-31

Filed 2026-05-13

Q/Q Activity

+0 / −0 / ↑0 / ↓1

vs 2025-12-31

Firm Profile & Key People
Name Title / Status Ownership Type

Top Adds (vs prior quarter)

  • No increased positions.
Show all 0

Top Trims

  • AVANTOR INC-$50.7M -31.6%
Show all 1

New Positions

  • No new positions this quarter.
Show all 0

Exited Positions

  • No exits this quarter.
Show all 0
All Holdings

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 AVANTOR INC AVTR 05352A100 $109.8M 100.00% 14,000,000 SH
Filing History
Period Filed AUM Holdings Accession
2026-03-31 2026-05-13 $109.8M 1 0001172661-26-001765
2025-12-31 2026-02-17 $160.4M 1 0001172661-26-000966
2025-09-30 2025-11-14 $174.7M 1 0001172661-25-004866