SUMMIT PARTNERS L P

BOSTON, MA · CIK 830588 · 13F filing filed 2025-11-04

SEC-registered investment adviser since 2005 · limited partnership

Assets managed$42.0bn
Staff218 · 118 in investment roles
Main clients (by assets)Private funds 100%
Private funds87 · $42.0bn gross assets
Websitesummitpartners.com
Form ADV · 2026-08-20SEC adviser record

Legal entitySUMMIT PARTNERS, L.P. (US)

$924.3m reported value -34.8% vs Q2 2025

8positions

100.0%in top 10

1 new 0 added 2 reduced 0 sold out vs Q2 2025

Holdings, Q3 2025

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change	Shares change
1	KLAVIYO INC COM SER A KVYO	KVYO	18,852,778	$522.0m56.48%	56.48%	Reduced -12.0m	-11,975,000 -38.8%
2	LIFESTANCE HEALTH GROUP INC COM LFST	LFST	33,524,715	$184.4m19.95%	19.95%	Reduced -8.4m	-8,407,643 -20.1%
3	AVEANNA HEALTHCARE HLDGS INC COM AVAH	AVAH	9,651,422	$85.6m9.26%	9.26%	Unchanged
4	A K A BRANDS HLDG CORP COM SHS AKA	AKA	6,053,693	$58.4m6.32%	6.32%	Unchanged
5	JAMF HLDG CORP COM JAMF	JAMF	4,475,381	$47.9m5.18%	5.18%	Unchanged
6	SOLO BRANDS INC COM CL A NEW SBDS	SBDS	1,100,870	$16.6m1.80%	1.80%	New
7	MACOM TECH SOLUTIONS HLDGS I COM MTSI	MTSI	47,650	$5.9m0.64%	0.64%	Unchanged
8	A10 NETWORKS INC COM ATEN	ATEN	187,367	$3.4m0.37%	0.37%	Unchanged

Stakes above 5%

Companies where this manager has reported owning more than 5% of a class of shares, on Schedule 13D (may seek influence) or 13G (passive): its latest filing for each, from 19 Dec 2024 on.

Company	Ticker	Stake	Change	Schedule	Last filed
KLAVIYO INC KVYO · 13G · filed 2025-11-13	KVYO	12.0%≈ $284.7m	-8.8 pts	13G	2025-11-13
LIFESTANCE HEALTH GROUP INC LFST · 13G · filed 2026-08-11	LFST	6.1%≈ $249.7m	-1.4 pts	13G	2026-08-11

Trades reported as a company insider in Q3 2025

Owning 10% or more of a company, or having someone on its board, makes this manager an insider there: it reports its trades in that company's shares on Form 4 within two business days. Open-market and private purchases and sales only.

Date	Company	Ticker	Trade	Shares	Value	Their holding
2025-09-08	KLAVIYO INC 10% owner · See footnotes	KVYO	Sold	4,000,000	$127.5m4.0m shares	-100%
2025-08-25	KLAVIYO INC 10% owner · See footnote	KVYO	Sold	975,000	$29.3m975.0k shares	-100%
2025-08-18	LIFESTANCE HEALTH GROUP INC 10% owner	LFST	Sold	8,407,643	$42.6m8.4m shares	-20%
2025-08-13	KLAVIYO INC 10% owner · See footnotes	KVYO	Sold	6,500,000	$195.1m6.5m shares	-93%