Pinnbrook Capital Management LP
PERIOD 2026-Q2 (filed 2026-08-12) · SOURCE: SEC EDGAR (PUBLIC)
Holdings as of the 2026-Q2 13F-HR filing (filed 2026-08-12). 13F is disclosed up to 45 days after quarter-end.
What a 13F does — and does not — show
These figures come from Form 13F, a quarterly filing that large US institutional managers must submit to the SEC. It is a useful window, but a partial and lagged one, so read it carefully:
- It is a snapshot, up to 45 days old. A 13F shows what a manager held on the last day of a quarter, filed up to 45 days later — the fund may have traded since.
- Long US-listed stocks only. It excludes short positions, cash, bonds, most derivatives, and non-US or private holdings, so it is not the fund’s whole portfolio.
- Reported 13F value is not assets under management. Every share and concentration figure below is a percentage of the reported 13F value only — not the firm’s total assets.
- It describes, it does not recommend. A large or long-held position is not an endorsement, and none of this is investment advice.
Concentration
Share of reported portfolio value. Long US-listed equity positions as filed; percentages are of reported 13F value, which excludes shorts, cash, non-US and private holdings.
| Tier | Reported value | Share |
|---|---|---|
| Top position | $45M | 7.4% |
| Top 5 | $134M | 22.3% |
| Top 10 | $214M | 35.6% |
Top holdings
| # | Security | Shares | Reported value | % of value |
|---|---|---|---|---|
| 1 | CSX CSX CORP added | 939,978 | $45M | 7.4% |
| 2 | KGS KODIAK GAS SVCS INC added | 391,854 | $29M | 4.9% |
| 3 | JBL JABIL INC added | 58,867 | $23M | 3.8% |
| 4 | NTRA NATERA INC new | 69,300 | $19M | 3.1% |
| 5 | WAB WABTEC added | 69,107 | $19M | 3.1% |
| 6 | PWR QUANTA SVCS INC new | 23,734 | $17M | 2.8% |
| 7 | TKR TIMKEN CO new | 113,500 | $16M | 2.7% |
| 8 | ATI ATI INC added | 82,081 | $16M | 2.7% |
| 9 | TXN TEXAS INSTRS INC new | 50,400 | $15M | 2.5% |
| 10 | ARMK ARAMARK new | 257,700 | $15M | 2.4% |
| 11 | DTM DT MIDSTREAM INC new | 97,009 | $14M | 2.4% |
| 12 | STX SEAGATE TECHNOLOGY HLDNGS PL added | 13,840 | $13M | 2.2% |
Sector mix
Reported 13F value by sector, as a share of the largest positions we rank. Sectors come from company reference data joined to each holding. 6% of this value is not classified to a sector and is excluded from the mix. Long US-listed equity positions as filed.
| Sector | Reported value | Share |
|---|---|---|
| Industrials | $149M | 45.4% |
| Technology | $73M | 22.3% |
| Energy | $44M | 13.3% |
| Healthcare | $19M | 5.7% |
| Consumer Defensive | $13M | 3.9% |
| Communication Services | $9M | 2.8% |
How this filer invests
Reproducible measures computed from the positions in this filer’s own 13F filings — not from any outside estimate.
How concentrated the book is
Across 88 reported positions. Shares are of reported 13F value (long US-listed equity), which is not the firm’s total assets. The concentration index (HHI) is the sum of each position’s squared weight — higher means a book concentrated in fewer names.
How much the book turned over
Between the 2026-Q1 and 2026-Q2 filings, on the stable identity of each holding (share classes combined). New positions and exits are counted by presence; adds and trims by share count, and a share-count change matching a standard split ratio with the value held steady is not counted as either.
Long-term holdings vs. higher turnover
Of its 20 largest reported positions, 0 have appeared in its 5 most recent consecutive quarterly filings (more than a year), and 5 are more recent. This filer reads as a higher-turnover book: few of its largest positions have persisted for more than a year. 15 could not be classified: the stored filing history has a gap before the run reaches a year, and a gap is not counted as not held.
Directional only, measured over the filer’s largest reported positions across the quarters we track. 13F is a quarter-end snapshot, so a name can be held continuously yet slip in and out of the largest positions; this is a starting question, not a verdict.
Quarter-over-quarter changes — filed 2026-08-12
What changed between the 2026-Q1 and 2026-Q2 13F filings. New positions and exits reflect the tracked snapshot; adds and trims are measured on reported value (split-invariant), and moves under $0.25M are omitted as noise.
Between the 2026-Q1 and 2026-Q2 filings, this filer opened its largest new position in NTRA, fully exited SLB, added most to CSX, and trimmed CW the most. This describes what the 13F reported — not a recommendation.
New positions 71
- NTRA$19M
- PWR$17M
- TKR$16M
- TXN$15M
- ARMK$15M
- DTM$14M
Exited 16
- SLB$6M
- LRCX$6M
- DVN$6M
- MRK$6M
- LIN$5M
- AMAT$5M
Largest adds
- CSX$42M
- KGS$19M
- JBL$17M
- WAB$17M
- ATI$15M
- STX$12M
Largest trims
- CW$4M
- EMBJ$510K
- MTZ$308K
Portfolio trend
Reported 13F value and position count by filing quarter (independent scales).
Frequently asked
What does Pinnbrook Capital Management LP own?
Pinnbrook Capital Management LP reported 88 long US-listed equity positions worth $601M in its 2026-Q2 13F filing.
What changed in Pinnbrook Capital Management LP's portfolio last quarter?
Pinnbrook Capital Management LP's 2026-Q2 filing is compared against its prior 13F to identify new positions, exits, and the largest increases and reductions, measured on reported value.
Where does this data come from?
Holdings are parsed from SEC Form 13F-HR filings on EDGAR (public filings). 13F is disclosed up to 45 days after quarter-end and reflects long US-listed equity positions only. Informational, not investment advice.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It is filed up to 45 days after quarter-end, so it is backward-looking — the manager may have traded since — and it covers long US-listed equities only, not short positions, cash, or private holdings. Reading a 13F tells you what a manager owned, not whether you should own it.