140 Summer Partners LP is an SEC-registered investment adviser based in New York, NY that reports managing 3 hedge funds on Form ADV. It reports $3.9 billion in regulatory assets under management. Its private funds, of all types, hold $6.6 billion in gross assets. Its disclosed U.S. stock holdings returned an estimated +5.8% 2026 YTD through Jun 30 (S&P 500: +9.5%), based on 13F filings. Over a longer period they returned an estimated +51.5% from Q3 2024 to Q2 2026, compared with +37.2% for the S&P 500, based on 13F filings.
- Regulatory assets under management
- $3.9 billionForm ADV Item 5.F
- Gross assets of private funds
- $6.6 billionAll private fund types, Form ADV
- Hedge funds managed
- 33 private funds in total
- Employees
- 14Form ADV Item 5.A
- Registration
- SEC-registered adviserCRD 308929
- Latest Form ADV
- 03/20/2026Disciplinary disclosures: none reported
Estimated 13F portfolio performance
Estimated by AltMountain, derived from the firm’s public Form 13F filings. Not reported by the firm and not the return of any fund.
| Quarter | Est. 13F return | S&P 500 |
|---|---|---|
| Q2 2026 | +12.9% | +14.8% |
| Q1 2026 | -6.2% | -4.6% |
| Q4 2025 | +5.6% | +2.4% |
| Q3 2025 | +13.5% | +7.8% |
| Q2 2025 | +5.9% | +10.4% |
| Q1 2025 | +2.1% | -4.5% |
| Q4 2024 | -3.1% | +2.1% |
| Q3 2024 | +14.0% | +5.4% |
Estimate of the firm's disclosed long U.S. stock portfolio from its quarterly 13F filings, holding each quarter-end portfolio to the next quarter-end at prices implied by all 13F filers. It is a price return before dividends and fees, ignores shorts, options, bonds, cash and trading within the quarter, and is not the return of any fund. Disclosures
Manager of this firm? Report your fund’s actual net return, or email hello@altmountain.com to correct or remove this estimate. Removal requests from the firm are honored.
13F holdings as of Jun 30, 2026
All 20 share positions ($1,234,510,974) reported by 140 Summer Partners LP on Form 13F for the quarter ended Jun 30, 2026, filed Aug 14, 2026. Shown as filed with the SEC. Original filing on SEC.gov ↗
| Stock | Value | % of 13F portfolio | Shares | Shares vs prior quarter |
|---|---|---|---|---|
| Viasat Inc | $201,787,712 | 16.35% | 2,246,829 | +147.46% |
| Mastec Inc | $111,573,978 | 9.04% | 268,168 | -18.54% |
| Kodiak Gas Svcs Inc | $97,829,027 | 7.92% | 1,302,130 | +0.48% |
| Gaming & Leisure P | $83,000,491 | 6.72% | 1,863,923 | Unchanged |
| Somnigroup International Inc | $78,030,501 | 6.32% | 995,287 | +38.84% |
| Vistra Corp | $74,116,854 | 6.00% | 467,231 | -3.21% |
| Viking Holdings LTD | $71,192,557 | 5.77% | 680,162 | -40.83% |
| Capital One Finl Corp | $60,279,088 | 4.88% | 300,464 | -23.41% |
| Aercap Holdings NV | $58,210,683 | 4.72% | 399,305 | -21.48% |
| Huntington Bancshares Inc | $50,561,669 | 4.10% | 2,851,758 | -13.43% |
| Bitdeer Technologies Group | $50,075,246 | 4.06% | 3,155,340 | +310.03% |
| Cipher Digital Inc | $49,762,342 | 4.03% | 2,031,116 | New |
| Brookdale SR Living Inc | $47,321,012 | 3.83% | 2,941,020 | +2.51% |
| Telephone & Data SYS Inc | $35,849,107 | 2.90% | 968,633 | -27.54% |
| Nvent Elec PLC | $35,098,076 | 2.84% | 206,934 | New |
| Pg&e Corp | $33,779,421 | 2.74% | 2,008,289 | -59.29% |
| Bank Hawaii Corp | $31,775,151 | 2.57% | 389,927 | -3.12% |
| Grupo Aeromexico Sab De CV | $23,370,984 | 1.89% | 1,298,388 | Unchanged |
| Flowserve Corp | $21,303,572 | 1.73% | 287,265 | New |
| Braskem SA | $19,593,503 | 1.59% | 8,030,124 | New |
Changes since Mar 31, 2026
Comparing the share counts in the two quarter-end filings: 4 new positions, 4 sold out, 5 increased, 9 reduced and 2 unchanged.
New positions
| Stock | Value | Shares |
|---|---|---|
| Cipher Digital Inc | $49,762,342 | 2,031,116 |
| Nvent Elec PLC | $35,098,076 | 206,934 |
| Flowserve Corp | $21,303,572 | 287,265 |
| Braskem SA | $19,593,503 | 8,030,124 |
Sold out
| Stock | Value at Mar 31, 2026 | Shares held then |
|---|---|---|
| T-mobile US Inc | $81,222,382 | 386,718 |
| Echostar Corp | $62,097,908 | 530,434 |
| JBT Marel Corporation | $40,304,880 | 315,202 |
| Optimum Communications Inc | $3,231,432 | 2,485,717 |
Largest increases
| Stock | Change in shares | Change | Value now | Shares now |
|---|---|---|---|---|
| Viasat Inc | +1,338,859 | +147.46% | $201,787,712 | 2,246,829 |
| Bitdeer Technologies Group | +2,385,795 | +310.03% | $50,075,246 | 3,155,340 |
| Somnigroup International Inc | +278,431 | +38.84% | $78,030,501 | 995,287 |
| Brookdale SR Living Inc | +72,020 | +2.51% | $47,321,012 | 2,941,020 |
| Kodiak Gas Svcs Inc | +6,208 | +0.48% | $97,829,027 | 1,302,130 |
Largest reductions
| Stock | Change in shares | Change | Value now | Shares now |
|---|---|---|---|---|
| Pg&e Corp | -2,924,474 | -59.29% | $33,779,421 | 2,008,289 |
| Viking Holdings LTD | -469,379 | -40.83% | $71,192,557 | 680,162 |
| Mastec Inc | -61,052 | -18.54% | $111,573,978 | 268,168 |
| Capital One Finl Corp | -91,858 | -23.41% | $60,279,088 | 300,464 |
| Aercap Holdings NV | -109,261 | -21.48% | $58,210,683 | 399,305 |
| Telephone & Data SYS Inc | -368,098 | -27.54% | $35,849,107 | 968,633 |
| Huntington Bancshares Inc | -442,559 | -13.43% | $50,561,669 | 2,851,758 |
| Vistra Corp | -15,503 | -3.21% | $74,116,854 | 467,231 |
| Bank Hawaii Corp | -12,538 | -3.12% | $31,775,151 | 389,927 |
Each list shows up to 20 positions, largest first by dollar amount. Changes compare two quarter-end snapshots, with the earlier share count adjusted for stock splits AltMountain detected. They do not show when, or at what price, anything was bought or sold.
From public Form 13F filings, not verified. Form 13F is filed up to 45 days after the quarter ends, so positions may have changed. It lists only certain long positions in U.S.-listed stocks and exchange-traded funds; options are not shown here, and short positions, most bonds, cash, non-U.S. securities and private investments are not reported at all, so a holding may be one side of a hedge. A filing covers the manager as a whole, not any single fund, and filings contain errors. This is not investment advice or a recommendation to buy or sell any security. Disclosures
Hedge funds filing Form D (2)
Matched to this firm by the fund names and related persons in each Form D. The list may be incomplete.
Private funds reported on Form ADV (1)
As reported in the adviser's Form ADV filed Mar 26, 2024. Funds also listed from Form D are shown above.
Fund vehicles: feeder funds and single-deal vehicles (2)
Feeder funds invest through a master fund; single-deal vehicles (SPVs, co-investments, series) hold one investment.
From SEC filings. Firm data comes from the SEC's Form ADV data as of Oct 2, 2026; performance estimates come from Form 13F. AltMountain has not verified this information, and it is not an offer, solicitation or recommendation. Full disclosures