SUMMIT PARTNERS L P — 13F Holdings & Portfolio
CIK 830588 · latest 13F-HR filed 2026-05-08
SUMMIT PARTNERS L P manages $670.2M in 13F-reported U.S. long-equity assets across 7 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are KVYO (54.74%), LFST (27.76%), AKA (9.32%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 0 new positions, exited 1, added to 2, and trimmed 4.
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.
$670.2M
Long-equity book
7
Distinct positions
2026-03-31
Filed 2026-05-08
+0 / −1 / ↑2 / ↓4
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- MACOM TECH SOLUTIONS HLDGS I$2.8M +34.1%
- A10 NETWORKS INC$1.3M +39.6%
Top Trims
- KLAVIYO INC-$245.3M -40.1%
- LIFESTANCE HEALTH GROUP INC-$49.9M -21.2%
- AVEANNA HEALTHCARE HLDGS INC-$26.6M -43.1%
- SOLO BRANDS INC-$2.5M -37.9%
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 | KLAVIYO INC | KVYO | 49845K101 | $366.9M | 54.74% | 18,852,778 | SH |
| 2 | LIFESTANCE HEALTH GROUP INC | LFST | 53228F101 | $186.1M | 27.76% | 29,209,776 | SH |
| 3 | A K A BRANDS HLDG CORP | AKA | 00152K200 | $62.4M | 9.32% | 6,053,693 | SH |
| 4 | AVEANNA HEALTHCARE HLDGS INC | AVAH | 05356F105 | $35.1M | 5.23% | 5,451,422 | SH |
| 5 | MACOM TECH SOLUTIONS HLDGS I | MTSI | 55405Y100 | $10.9M | 1.63% | 49,273 | SH |
| 6 | A10 NETWORKS INC | ATEN | 002121101 | $4.6M | 0.69% | 200,065 | SH |
| 7 | SOLO BRANDS INC | DTCB | 83425V203 | $4.1M | 0.62% | 1,100,870 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-08 | $670.2M | 7 | 0001172661-26-001623 |
| 2025-12-31 | 2026-02-06 | $1.05B | 8 | 0000830588-26-000001 |