SUMMIT PARTNERS L P — 13F Holdings & Portfolio
CIK 830588 · latest 13F-HR filed 2026-07-30
SUMMIT PARTNERS L P manages $608.9M in 13F-reported U.S. long-equity assets across 5 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are KVYO (46.75%), LFST (41.00%), AKA (10.65%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 0 new positions, exited 2, added to 2, and trimmed 2.
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.
18TH FLOOR
BOSTON, MA 02116
$608.9M
Long-equity book
5
Distinct positions
2026-06-30
Filed 2026-07-30
+0 / −2 / ↑2 / ↓2
vs 2026-03-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- LIFESTANCE HEALTH GROUP INC$63.6M +34.2%
- A10 NETWORKS INC$2.8M +61.6%
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 | $284.7M | 46.75% | 18,852,778 | SH |
| 2 | LIFESTANCE HEALTH GROUP INC | LFST | 53228F101 | $249.7M | 41.00% | 23,310,115 | SH |
| 3 | A K A BRANDS HLDG CORP | AKA | 00152K200 | $64.8M | 10.65% | 6,053,693 | SH |
| 4 | A10 NETWORKS INC | ATEN | 002121101 | $7.5M | 1.23% | 200,065 | SH |
| 5 | MACOM TECH SOLUTIONS HLDGS I | MTSI | 55405Y100 | $2.3M | 0.38% | 6,005 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-07-30 | $608.9M | 5 | 0001172661-26-002948 |
| 2026-03-31 | 2026-05-08 | $670.2M | 7 | 0001172661-26-001623 |
| 2025-12-31 | 2026-02-06 | $1.05B | 8 | 0000830588-26-000001 |