New Mountain Capital, L.L.C. holds a concentrated book of 1 stock worth $138.6M as of Q2 2026 (disclosed Aug 14, 2026, a ~45-day 13F lag). This quarter they opened R1 RCM Inc. Their largest long position is Avantor Inc at 100% of the equity book.
Top-heavy: concentrated book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
100% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Avantor Inc COM | $138.6M | 14.00M | 100.0% | —Held |
The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1407718/holdings"
Use Arkolith to show New Mountain Capital, L.L.C.'s latest holdings, largest changes, and filing provenance.
As-of date vs the date the SEC received each filing
| Quarter | As of | Filed | Positions | Value | Form |
|---|---|---|---|---|---|
| Q2 2026 | Jun 30, 2026 | Aug 14, 2026 | 1 | $138.6M | 13F-HR |
| Q1 2026 | Mar 31, 2026 | May 13, 2026 | 1 | $109.8M | 13F-HR |
| Q4 2025 | Dec 31, 2025 | Feb 17, 2026 | 1 | $160.4M | 13F-HR |
| Q3 2025 | Sep 30, 2025 | Nov 14, 2025 | 1 | $174.7M | 13F-HR |
| Q2 2025 | Jun 30, 2025 | Aug 14, 2025 | 1 | $188.4M | 13F-HR |
| Q1 2025 | Mar 31, 2025 | May 15, 2025 | 1 | $226.9M | 13F-HR |
| Q4 2024 | Dec 31, 2024 | Feb 13, 2025 | 1 | $295.0M | 13F-HR |
| Q3 2024 | Sep 30, 2024 | Nov 14, 2024 | 2 | $1.7B | 13F-HR |
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.