Q2 2026 13F · SEC CIK 201772

Essex Investment Management Co LLC

Asset managerFiled 2026-08-06 for Q2 2026. Open the filing ↗ · All SEC filings ↗

Reported 13F value: $763.4M
Reported positions: 306
Top holdings a year, 3 yrs: +43.4%
Assets under management: $712.7M

Essex Investment Management Co LLC is an asset manager that reported 306 positions worth $763.4M in its Q2 2026 13F, filed 2026-08-06. Its largest holdings were Tower Semiconductor Ltd (TSEM, 3.6%), Lincoln Edl Svcs Corp (LINC, 2.2%), Kiniksa Pharmaceuticals Intl P (KNSA, 2.0%). A portfolio copying its top holdings returned 43.4% a year over the last 3 years, against 20.4% for the S&P 500.

Essex Investment Management Co LLC holdings largest 50 of 306 positions.

Weights are shares of the filer's total reported 13F value, compared with Q1 2026. Share changes may reflect splits; weight changes also reflect price moves. A 13F shows long US-listed positions only, up to 135 days after the fact.

Essex Investment Management Co LLC 13F holdings
Stock	% of 13F value	Q1 2026	Shares	Share change	Reported value
TSEMTower Semiconductor Ltd	3.6%	3.2%	105,543	-9.0%	$27.5M
LINCLincoln Edl Svcs Corp	2.2%	2.3%	340,366	-4.2%	$17.0M
KNSAKiniksa Pharmaceuticals Intl P	2.0%	1.9%	241,382	-3.2%	$15.4M
OUSTOuster Inc	1.9%	—	226,028	—	$14.1M
LGNDLigand Pharmaceuticals Inc	1.8%	1.8%	43,567	-25.5%	$13.8M
CECOCeco Environmental Corp	1.8%	1.5%	150,416	-4.3%	$13.6M
STRLSterling Infrastructure Inc	1.8%	2.1%	16,155	-49.6%	$13.6M
AIPArteris Inc	1.8%	0.8%	277,665	-4.4%	$13.5M
MIRMMirum Pharmaceuticals Inc	1.6%	1.6%	105,669	-2.5%	$12.4M
AGXArgan, Inc.	1.6%	1.4%	15,467	-3.9%	$12.4M
GHMGraham Corp	1.5%	1.6%	93,405	-27.2%	$11.6M
DRSLeonardo Drs Inc	1.4%	1.8%	250,215	-4.3%	$10.7M
ADPTAdaptive Biotechnologies Corp	1.3%	1.1%	472,763	-4.2%	$10.1M
WERNWerner Enterprises Inc	1.3%	—	231,625	—	$10.1M
HCIHci Group Inc	1.3%	1.4%	56,260	-2.4%	$9.9M
GEVGe Vernova Inc	1.3%	1.1%	8,283	-0.4%	$9.7M
COHUCohu Inc	1.3%	0.9%	131,170	-31.6%	$9.7M
AAPLApple Inc	1.2%	1.3%	32,427	-0.5%	$9.4M
AMSCAmerican Superconductor Corp	1.2%	1.2%	221,933	-2.5%	$9.2M
BWAYBrainsway Ltd	1.2%	1.3%	592,606	-4.2%	$9.2M
TTITetra Technologies Inc D	1.1%	1.0%	741,007	-4.3%	$8.4M
LYTSLsi Inds Inc Ohio	1.0%	0.8%	295,820	+7.9%	$7.9M
MRVLMarvell Technology Inc	1.0%	—	25,911	—	$7.7M
KTOSKratos Defense & Sec Solutio	1.0%	1.8%	153,576	-3.3%	$7.7M
TVTXTravere Therapeutics Inc	1.0%	0.8%	133,866	-17.2%	$7.6M
GSGoldman Sachs Group Inc	1.0%	1.0%	7,513	-0.6%	$7.6M
PATKPatrick Inds Inc	1.0%	0.8%	82,960	+79.5%	$7.4M
ORNOrion Group Hldgs Inc	1.0%	0.8%	442,603	-4.2%	$7.4M
ASMLAsml Hldg NV	0.9%	0.7%	3,538	-0.5%	$7.0M
AMBAAmbarella Inc	0.9%	0.7%	79,997	-2.9%	$6.9M
NVCRNovocure Ltd	0.9%	0.8%	439,648	-2.8%	$6.7M
AMZNAmazon Com Inc Com	0.8%	0.9%	27,062	-0.5%	$6.4M
AVPTAvepoint Inc	0.8%	0.8%	571,541	+14.7%	$6.4M
WMSAdvanced Drainage Systems Inc	0.8%	0.9%	40,413	-0.4%	$6.3M
SMTCSemtech Corp	0.8%	—	38,226	—	$6.2M
OIIOceaneering Intl Inc	0.8%	0.9%	151,463	-4.4%	$6.1M
ECGEverus Constr Group	0.8%	0.7%	36,377	-4.5%	$6.0M
AEMAgnico Eagle Mines Ltd	0.8%	1.2%	38,462	-0.5%	$6.0M
LQDALiquidia Corporation	0.8%	—	74,743	—	$6.0M
WLDNWilldan Group Inc	0.8%	0.9%	74,890	-4.3%	$5.9M
FEIMFrequency Electrs Inc	0.8%	0.7%	89,043	-4.3%	$5.9M
MSFTMicrosoft Corp	0.8%	0.9%	15,714	-0.5%	$5.9M
MAMAMamas Creations Inc	0.8%	0.8%	326,938	-4.3%	$5.8M
XERSXeris Biopharma Holdings Inc	0.7%	0.7%	715,608	-4.3%	$5.7M
PKEPark Aerospace Corp	0.7%	—	143,663	—	$5.5M
BDSXBiodesix Inc	0.7%	—	241,915	—	$5.5M
XMTRXometry Inc	0.7%	—	55,919	—	$5.4M
BXCBluelinx Hldgs Inc	0.7%	—	86,593	—	$5.4M
MITKMitek Sys Inc	0.7%	—	263,913	—	$5.3M
CXDOCrexendo Inc	0.7%	0.7%	710,874	-4.3%	$5.3M

What Essex Investment Management Co LLC bought and sold in Q2 2026, against Q1 2026.

New positions

Q1 2026's filing was too long to tell new positions apart.

Added to

PATK Patrick Inds Inc+79.5% shares
AVPT Avepoint Inc+14.7% shares
LYTS Lsi Inds Inc Ohio+7.9% shares

Reduced

STRL Sterling Infrastructure Inc-49.6% shares
COHU Cohu Inc-31.6% shares
GHM Graham Corp-27.2% shares
LGND Ligand Pharmaceuticals Inc-25.5% shares
TVTX Travere Therapeutics Inc-17.2% shares
TSEM Tower Semiconductor Ltd-9.0% shares

Left the top 50

Share counts compared with the Q1 2026 13F; a split also changes share counts. The latest filing lists more than 50 positions, so a position that left the top 50 may still be held.

How the holdings did against the S&P 500.

1 year: +54.4% /yr; S&P 500 +20.1%
3 years: +43.4% /yr; S&P 500 +20.4%
5 years: +16.4% /yr; S&P 500 +11.6%

A portfolio of the filer's 20 largest 13F positions, weighted by value and rebuilt each quarter on the day the filing became public. 13Fs show long US-listed positions only, so this is an estimate of the stock picks, not the fund's reported returns.

Reported 13F value by quarter.

13F value by quarter
Quarter	13F value	Positions
Q2 2026	$763.4M	306
Q1 2026	$631.7M	305
Q4 2025	$655.9M	306
Q3 2025	$653.4M	299
Q2 2025	$550.0M	298
Q1 2025	$479.4M	303
Q4 2024	$556.1M	307
Q3 2024	$573.7M	302
Q2 2024	$534.7M	302
Q1 2024	$506.7M	306
Q4 2023	$507.9M	315
Q3 2023	$612.7M	356

Questions about Essex Investment Management Co LLC's portfolio

What stocks does Essex Investment Management Co LLC own?

Essex Investment Management Co LLC's latest 13F, for Q2 2026 and filed Aug 6, 2026, lists 306 positions worth $763.4M. The largest are Tower Semiconductor Ltd (TSEM) at 3.6%, Lincoln Edl Svcs Corp (LINC) at 2.2%, Kiniksa Pharmaceuticals Intl P (KNSA) at 2.0%, Ouster Inc (OUST) at 1.9% and Ligand Pharmaceuticals Inc (LGND) at 1.8%.

What did Essex Investment Management Co LLC buy last quarter?

In Q2 2026, Essex Investment Management Co LLC added Patrick Inds Inc (PATK) (+79.5% shares), Avepoint Inc (AVPT) (+14.7% shares) and Lsi Inds Inc Ohio (LYTS) (+7.9% shares), compared with its Q1 2026 filing.

What did Essex Investment Management Co LLC sell last quarter?

In Q2 2026, Essex Investment Management Co LLC cut from its top 50 Globalstar Inc (GSAT), cut from its top 50 Insmed Inc (INSM), cut from its top 50 Amprius Technologies Inc (AMPX), cut from its top 50 Primoris Svcs Corp (PRIM), cut from its top 50 Mirion Technologies Inc (MIR), Sterling Infrastructure Inc (STRL) (-49.6% shares), Cohu Inc (COHU) (-31.6% shares) and Graham Corp (GHM) (-27.2% shares), compared with its Q1 2026 filing.

How has Essex Investment Management Co LLC's portfolio performed?

A portfolio copying Essex Investment Management Co LLC's 20 largest 13F holdings each quarter, from the day each filing was public, returned +43.4% a year over the last 3 years, against +20.4% for the S&P 500. Over 1 year: +54.4% against +20.1%. Over 5 years: +16.4% a year against +11.6%.

When is Essex Investment Management Co LLC's next 13F filing due?

13F filings are due 45 days after each quarter ends. Essex Investment Management Co LLC's filing for the quarter ending Sep 30, 2026 is due by Nov 14, 2026; this page updates the day after it is published.

How much money does Essex Investment Management Co LLC manage?

Essex Investment Management Co LLC reported $712.7M of regulatory assets under management on its latest SEC Form ADV. Its 13F, which covers only US-listed stocks and options, totals $763.4M.