SUMMIT PARTNERS L P

BOSTON, MA · CIK 830588 · 13F filing filed 2024-01-12

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)

$2.7bn reported value -6.1% vs Q3 2023

11positions

100.0%in top 10

0 new 0 added 2 reduced 0 sold out vs Q3 2023

Holdings, Q4 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	47,741,629	$1.3bn48.39%	48.39%	Reduced -1.8m	-1,770,318 -3.6%
2	ENGAGESMART INC COMMON STOCK ESMT	ESMT	25,004,973	$572.6m20.89%	20.89%	Unchanged
3	LIFESTANCE HEALTH GROUP INC COM LFST	LFST	45,734,703	$358.1m13.06%	13.06%	Unchanged
4	SOLO BRANDS INC COM CL A COM CL A		44,034,960	$271.3m9.90%	9.90%	Unchanged
5	JAMF HLDG CORP COM JAMF	JAMF	4,475,381	$80.8m2.95%	2.95%	Unchanged
6	A10 NETWORKS INC COM ATEN	ATEN	3,888,206	$51.2m1.87%	1.87%	Unchanged
7	A K A BRANDS HLDG CORP COM COM		5,766,152	$46.4m1.69%	1.69%	Reduced -63.0m	-62,989,551 -91.6%
8	CASA SYS INC COM COM		34,124,480	$18.1m0.66%	0.66%	Unchanged
9	MARKFORGED HOLDING CORPORATI COM COM		14,595,201	$12.0m0.44%	0.44%	Unchanged
10	MACOM TECH SOLUTIONS HLDGS I COM MTSI	MTSI	43,268	$4.0m0.15%	0.15%	Unchanged
11	8X8 INC NEW COM EGHT	EGHT	52,919	$200.0k0.01%	0.01%	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 Q4 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
2023-10-23	KLAVIYO INC 10% owner · See footnote	KVYO	Sold	1,770,318	$50.1m1.8m shares	-100%