SUMMIT PARTNERS L P

BOSTON, MA · CIK 830588 · 13F filing filed 2023-10-24

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)

$2.9bn reported value +111.4% vs Q2 2023

11positions

100.0%in top 10

1 new 0 added 1 reduced 0 sold out vs Q2 2023

Holdings, Q3 2023

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	49,511,947	$1.7bn58.54%	58.54%	New
2	ENGAGESMART INC COMMON STOCK ESMT	ESMT	25,004,973	$449.8m15.42%	15.42%	Unchanged
3	LIFESTANCE HEALTH GROUP INC COM LFST	LFST	45,734,703	$314.2m10.77%	10.77%	Unchanged
4	SOLO BRANDS INC COM CL A COM CL A		44,034,960	$224.6m7.70%	7.70%	Unchanged
5	JAMF HLDG CORP COM JAMF	JAMF	4,475,381	$79.0m2.71%	2.71%	Unchanged
6	A10 NETWORKS INC COM ATEN	ATEN	3,888,206	$58.4m2.00%	2.00%	Unchanged
7	A K A BRANDS HLDG CORP COM COM		68,755,703	$29.9m1.03%	1.03%	Reduced -2.1k	-2,125 0.0%
8	CASA SYS INC COM COM		34,124,480	$28.9m0.99%	0.99%	Unchanged
9	MARKFORGED HOLDING CORPORATI COM COM		14,595,201	$21.2m0.73%	0.73%	Unchanged
10	MACOM TECH SOLUTIONS HLDGS I COM MTSI	MTSI	43,268	$3.5m0.12%	0.12%	Unchanged
11	8X8 INC NEW COM EGHT	EGHT	52,919	$133.4k0.00%	0.00%	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 2023

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
2023-09-22	KLAVIYO INC 10% owner · See footnote	KVYO	Sold	4,919,165	$139.3m4.9m shares	-100%