Essex Investment Management Co LLC (CIK: 0000201772) is a financial institution headquartered at 125 High Street, Suite 1803, Boston, Massachusetts 02110. The firm regularly files Form 13F with the U.S. Securities and Exchange Commission (SEC), disclosing its equity holdings and investment positions.

As of the latest reporting period (2026-03-31), the institution manages a portfolio valued at $631.74 M, comprising 305 distinct securities. Over its filing history, it has submitted 53 Form 13F reports.

To view the institution’s full SEC filing history:
🔗 View All SEC Filings

Q1 2026 — Top-10 concentration: 19.9%. Quarterly turnover: 11.1%. ▲ 27 new, +83 added, −86 reduced, ×28 exited.

Top Buys

Q1 2026

1. NVCR Novocure Limited

+$4.93 M

2. SNDX Syndax Pharmaceuticals

+$4.65 M

3. MG Mistras Group

+$3.97 M

4. MITK Mitek Systems

+$3.72 M

5. MRVL Marvell Technology

+$3.59 M

Top Sells

Q1 2026

1. TSEM Tower Semiconductor

−$13.46 M

2. BBNX Beta Bionics

−$6.64 M

3. AGX Argan

−$6.28 M

4. UVE Universal Insurance Holdings

−$6 M

5. STRL Sterling Infrastructure

−$5.14 M

Stocks/ETFs

-3.69%

$631.74 M 100.00%

Options

$0 0.00%

Debt

$0 0.00%

Other

$0 0.00%

Name	Shares	Market Value	Weight	Change	Activity
Tower Semiconductor TSEM	115,933	$20.34 M	3.22%	▼ 76,695	Reduce -39.8%
Lincoln Educational Services Corporation LINC	355,304	$14.45 M	2.29%	▼ 33,515	Reduce -8.6%
Sterling Infrastructure STRL	32,057	$13.06 M	2.07%	▼ 12,628	Reduce -28.3%
Kiniksa Pharmaceuticals International PLC KNSA	249,278	$12 M	1.90%	▼ 1,697	Reduce -0.7%
Ligand Pharmaceuticals LGND	58,460	$11.67 M	1.85%	▼ 1,560	Reduce -2.6%
Leonardo Drs DRS	261,454	$11.64 M	1.84%	▲ 4,592	Add 1.8%
Kratos Defense & Security Solutions KTOS	158,844	$11.2 M	1.77%	▼ 31,350	Reduce -16.5%
Globalstar GSAT	165,665	$11 M	1.74%	▼ 1,724	Reduce -1.0%
Insmed Incorporated INSM	62,676	$10.25 M	1.62%	▲ 253	Add 0.4%
Graham Corporation GHM	128,294	$10.12 M	1.60%	▼ 12,397	Reduce -8.8%

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Essex Investment Management Co LLC's Portfolio

This portfolio view aggregates one or more SEC Form 13F filings submitted by Essex Investment Management Co LLC each quarter. Holdings are organized into Stocks/ETFs, Options, Debt, and Other, with transaction markers indicating New Buy, Add, Reduce, No Change, or Sold Out. Reported anomalies are corrected where possible, and share counts are adjusted to reflect corporate actions such as stock splits. Since 2013, we have collected 52 quarters of portfolio data for this firm, providing a transparent record of institutional strategy over time.

Options Exposure History

CALL PUT

Report Date	Type	Underlying Shares	Notional Value	% Change

Report Date	Bought/Sold (Sh.)	% Change	Qtr. End Shares	Reported Price

Stocks ETFs

Name	Shares	Value	% of Portfolio	% Change
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CALL PUT

Type	Name	Shares	Value	% of Portfolio	% Change
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Name	Amount	Value	% of Portfolio	% Change
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Essex Investment Management Co LLC Quarterly 13F Statistics

Discover detailed insights into Essex Investment Management Co LLC’s SEC Form 13F filings, including:

Quarterly changes in holdings
Portfolio turnover
Asset allocation trends
Top 10 stock and ETF positions

This page provides a transparent view of institutional strategies based on official SEC disclosures, helping investors track long‑term shifts since 2013.

Quarter	Holdings	Total Value	Turnover Rate	Asset Allocation	Top 10 Stock & ETF Holdings

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Essex Investment Management Co LLC's All 13F Filings

This section lists all SEC Form 13F filings submitted by Essex Investment Management Co LLC.

Form 13F must be filed within 45 days after the end of each calendar quarter and discloses the reporting manager, the securities held, their CUSIP numbers, the number of shares held at quarter-end, and the total reported market value.

Please note that the market value shown reflects reported holdings only and should not be considered a substitute for Assets Under Management (AUM), as cash positions are excluded.
Each filing entry includes a direct link to the original Form 13F document on the SEC’s EDGAR system .

Report For	Filed At	AUM	Holdings	Form Type	Source

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Insider Trading Activity (SEC Form 4)

This section tracks real-time insider transactions reported via SEC Form 4 filings. Unlike the quarterly 13F portfolio snapshots, these records reflect immediate buying and selling activity where the filer acts as a corporate insider. Use this data to spot timely market moves.

Date Top Line (Transaction Date): The date of the most recent insider transaction. Bottom Line (Filing Date): The date the transaction was filed with the SEC.	Value Total Value: The total monetary value of the transaction. (Shares × Price)	Shares Shares Traded: Number of shares bought or sold in this specific transaction. Adjusted for splits.	Position / Chg Top Line (Held): Total shares owned after the transaction. Bottom Line (Change %): The percentage change in holdings due to this trade.
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Data Source & Methodology: This table is sourced exclusively from SEC Form 4 filings and is adjusted for stock splits. It reflects active insider trading decisions and does not include passive beneficial ownership reported in 13F or 13D/G filings.

Essex Investment Management Co LLC 13F Filings, Portfolio & Analysis

Essex Investment Management Co LLC — Portfolio Overview & Company Profile

Portfolio Summary (Q1 2026)

Top Buys

Top Sells

Asset Allocation

Sector Allocation (Stocks)

Top Stock & ETF Holdings (Q1 2026)

Historical Portfolio Charts

Essex Investment Management Co LLC's Portfolio

Essex Investment Management Co LLC Quarterly 13F Statistics

Essex Investment Management Co LLC's All 13F Filings

Insider Trading Activity (SEC Form 4)