SUMMIT PARTNERS L P
Long book
$670.2M
Q1 2026
Positions
7
Top-10 weight
100%
concentration
Last quarter
+18.2%
SPY +14.8%
Turnover
13%
of book per quarter
Strategy in plain words
auto-generated from filingsSUMMIT PARTNERS L P is a concentrated fundamental stock-picker, running a $670.2M US long book across 7 positions.
The portfolio is extremely concentrated — the top 10 positions are almost the whole book. Turnover is modest: positions are typically held for years. Current anchor positions: KLAVIYO INC-A, LIFESTANCE HEALTH GROUP INC, AKA BRANDS HOLDING CORP, AVEANNA HEALTHCARE HOLDINGS, MACOM TECHNOLOGY SOLUTIONS H.
Over the last 9 quarters its long book ran on average 1.6pp per quarter behind the S&P 500, beating the index in 4 of 9 quarters. We rate its filings highest-signal: new buys here are worth attention.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
-3.3%
Q2 2024
+42.6%
Q3 2024
+12.5%
Q4 2024
-24.2%
Q1 2025
+3.2%
Q2 2025
-10.0%
Q3 2025
+15.2%
Q4 2025
-28.4%
Q1 2026
+18.2%
Sector allocation
Technology 57%
Healthcare 33%
Consumer discretionary 9%
Other 1%
Long book by quarter
What does SUMMIT PARTNERS own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| KVYO KLAVIYO INC-A | Technology | 18.9M | $366.9M | 54.7% | Held |
| LFST LIFESTANCE HEALTH GROUP INC | Healthcare | 29.2M | $186.1M | 27.8% | -12.9% |
| AKA AKA BRANDS HOLDING CORP | Consumer discretionary | 6.1M | $62.4M | 9.3% | Held |
| AVAH AVEANNA HEALTHCARE HOLDINGS | Healthcare | 5.5M | $35.1M | 5.2% | -27.8% |
| MTSI MACOM TECHNOLOGY SOLUTIONS H | Technology | 49.3K | $10.9M | 1.6% | +3.4% |
| ATEN A10 NETWORKS INC | Technology | 200.1K | $4.6M | 0.7% | +6.8% |
| SBDS SOLO BRANDS INC - CLASS A | Other | 1.1M | $4.1M | 0.6% | Held |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 8, 2026 | 7 | $670.2M | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 6, 2026 | 8 | $1.05B | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 4, 2025 | 8 | $924.3M | canonical | SEC ↗ |
| Q2 2025 | 13F-HR/ARESTATEMENT | Nov 4, 2025 | 7 | $1.42B | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Jul 16, 2025 | 7 | $1.42B | SEC ↗ | |
| Q1 2025 | 13F-HR | May 5, 2025 | 9 | $1.61B | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 4, 2025 | 8 | $2.23B | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Oct 31, 2024 | 9 | $2.24B | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Jul 18, 2024 | 9 | $1.68B | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 15, 2024 | 10 | $1.81B | canonical | SEC ↗ |
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