Essex Investment Management Co LLC holds a diversified book of 306 stocks worth $763.4M as of Q2 2026 (disclosed Aug 6, 2026, a ~37-day 13F lag). This quarter they opened Werner Enterprises Inc and trimmed Tower Semiconductor Ltd. Their largest long position is Tower Semiconductor Ltd at 4% of the equity book. Cloning the disclosed picks since 2025 would be +25% (+34.5%/yr). That is a simulation of the disclosed long book, not audited returns.
Following at the filing date actually beat the quarter-end book by 7.3 points over this window.
Growth of $10,000 cloning Essex Investment Management Co LLC's disclosed long 13F book, rebalanced on each filing date (so it reflects each quarter's actual reporting lag, ~37 days for the latest filing, with no look-ahead), total-return basis (dividends reinvested), derived from end-of-day prices. “Their reported book” values the same picks from quarter-end, before they were public. S&P 500 is SPY total return over the same window. Excludes shorts, cash, options and non-13F holdings. Not investment advice.
Top-heavy: diversified book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
99% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
Other tracked managers holding the same core names as Essex Investment Management Co LLC
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| BlackRock, Inc. | 80 / 80 | $736.2B |
| GEODE CAPITAL MANAGEMENT, LLC | 80 / 80 | $230.8B |
| MORGAN STANLEY | 80 / 80 | $162.5B |
| UBS Group AG | 80 / 80 | $39.2B |
| SEI INVESTMENTS CO | 80 / 80 | $9.4B |
| GOLDMAN SACHS GROUP INC | 79 / 80 | $70.5B |
| BARCLAYS PLC | 79 / 80 | $27.8B |
| STATE STREET CORP | 78 / 80 | $445.9B |
Ranked by how many of Essex Investment Management Co LLC's top 80 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Tower Semiconductor Ltd COM | $27.5M | 105.5K | 3.6% | ▼−9.0% Reduced · −10K sh | |
| 2 | Lincoln Edl Svcs Corp COM | $17.0M | 340.4K | 2.2% | ▼−4.2% Reduced · −15K sh | |
| 3 | Kiniksa Pharmaceuticals Intl P COM | $15.4M | 241.4K | 2.0% | ▼−3.2% Reduced · −8K sh | |
| 4 | Ouster Inc COM | $14.1M | 226.0K | 1.9% | ▲+22% Added · +41K sh | |
| 5 | Ligand Pharmaceuticals Inc COM | $13.8M | 43.6K | 1.8% | ▼−25% Reduced · −15K sh | |
| 6 | Ceco Environmental Corp COM | $13.6M | 150.4K | 1.8% | ▼−4.3% Reduced · −7K sh | |
| 7 | Sterling Infrastructure Inc COM | $13.6M | 16.2K | 1.8% | ▼−50% Reduced · −16K sh | |
| 8 | Arteris Inc COM | $13.5M | 277.7K | 1.8% | ▼−4.3% Reduced · −13K sh | |
| 9 | Mirum Pharmaceuticals Inc COM | $12.4M | 105.7K | 1.6% | ▼−2.5% Reduced · −3K sh | |
| 10 | Argan Inc COM | $12.4M | 15.5K | 1.6% | ▼−3.9% Reduced · −631 sh | |
| 11 | Graham Corp COM | $11.6M | 93.4K | 1.5% | ▼−27% Reduced · −35K sh | |
| 12 | Leonardo DRS Inc COM | $10.7M | 250.2K | 1.4% | ▼−4.3% Reduced · −11K sh | |
| 13 | Adaptive Biotechnologies Corp COM | $10.1M | 472.8K | 1.3% | ▼−4.2% Reduced · −21K sh | |
| 14 | Werner Enterprises Inc COM | $10.1M | 231.6K | 1.3% | ▲New New position | |
| 15 | Hci Group Inc COM | $9.9M | 56.3K | 1.3% | ▼−2.4% Reduced · −1K sh | |
| 16 | Ge Vernova Inc COM | $9.7M | 8.3K | 1.3% | ▼−0.4% Reduced · −36 sh | |
| 17 | Cohu Inc COM | $9.7M | 131.2K | 1.3% | ▼−32% Reduced · −61K sh | |
| 18 | Apple Inc COM | $9.4M | 32.4K | 1.2% | ▼−0.5% Reduced · −153 sh | |
| 19 | American Superconductor Corp COM | $9.2M | 221.9K | 1.2% | ▼−2.5% Reduced · −6K sh | |
| 20 | Brainsway Ltd ADR | $9.2M | 592.6K | 1.2% | ▼−4.2% Reduced · −26K sh | |
| 21 | Tetra Technologies Inc Del COM | $8.4M | 741.0K | 1.1% | ▼−4.3% Reduced · −33K sh | |
| 22 | Lsi Inds Inc Ohio COM | $7.9M | 295.8K | 1.0% | ▲+7.9% Added · +22K sh | |
| 23 | Marvell Technology Inc COM | $7.7M | 25.9K | 1.0% | ▼−28% Reduced · −10K sh | |
| 24 | Kratos Defense & Sec Solutions COM | $7.7M | 153.6K | 1.0% | ▼−3.3% Reduced · −5K sh | |
| 25 | Travere Therapeutics Inc COM | $7.6M | 133.9K | 1.0% | ▼−17% Reduced · −28K sh | |
| 26 | Goldman Sachs Group Inc COM | $7.6M | 7.5K | 1.0% | ▼−0.6% Reduced · −43 sh | |
| 27 | Patrick Inds Inc COM | $7.4M | 83.0K | 1.0% | ▲+79% Added · +37K sh | |
| 28 | Orion Group Hldgs Inc COM | $7.4M | 442.6K | 1.0% | ▼−4.2% Reduced · −19K sh | |
| 29 | ASML Hldg NV ADR | $7.0M | 3.5K | 0.9% | ▼−0.5% Reduced · −18 sh | |
| 30 | Ambarella Inc COM | $6.9M | 80.0K | 0.9% | ▼−2.9% Reduced · −2K sh | |
| 31 | Novocure Ltd COM | $6.7M | 439.6K | 0.9% | ▼−2.8% Reduced · −13K sh | |
| 32 | Amazon Com Inc COM | $6.4M | 27.1K | 0.8% | ▼−0.5% Reduced · −146 sh | |
| 33 | Avepoint Inc COM | $6.4M | 571.5K | 0.8% | ▲+15% Added · +73K sh | |
| 34 | Advanced Drain Sys Inc Del COM | $6.3M | 40.4K | 0.8% | ▼−0.4% Reduced · −156 sh | |
| 35 | Semtech Corp COM | $6.2M | 38.2K | 0.8% | ▼−25% Reduced · −12K sh | |
| 36 | Oceaneering Intl Inc COM | $6.1M | 151.5K | 0.8% | ▼−4.4% Reduced · −7K sh | |
| 37 | Everus Constr Group COM | $6.0M | 36.4K | 0.8% | ▼−4.5% Reduced · −2K sh | |
| 38 | Agnico Eagle Mines Ltd COM | $6.0M | 38.5K | 0.8% | ▼−0.5% Reduced · −181 sh | |
| 39 | Liquidia Corporation COM | $6.0M | 74.7K | 0.8% | ▼−4.4% Reduced · −3K sh | |
| 40 | Willdan Group Inc COM | $5.9M | 74.9K | 0.8% | ▼−4.3% Reduced · −3K sh | |
| 41 | Frequency Electrs Inc COM | $5.9M | 89.0K | 0.8% | ▼−4.3% Reduced · −4K sh | |
| 42 | Microsoft Corp COM | $5.9M | 15.7K | 0.8% | ▼−0.5% Reduced · −77 sh | |
| 43 | Mamas Creations Inc COM | $5.8M | 326.9K | 0.8% | ▼−4.3% Reduced · −15K sh | |
| 44 | Xeris Biopharma Holdings Inc COM | $5.7M | 715.6K | 0.7% | ▼−4.3% Reduced · −32K sh | |
| 45 | Park Aerospace Corp COM | $5.5M | 143.7K | 0.7% | ▼−4.2% Reduced · −6K sh | |
| 46 | Biodesix Inc COM | $5.5M | 241.9K | 0.7% | ▲+83% Added · +110K sh | |
| 47 | Xometry Inc COM | $5.4M | 55.9K | 0.7% | ▲New New position | |
| 48 | Bluelinx Hldgs Inc COM | $5.4M | 86.6K | 0.7% | ▲New New position | |
| 49 | Mitek Sys Inc COM | $5.3M | 263.9K | 0.7% | ▼−4.2% Reduced · −12K sh | |
| 50 | Crexendo Inc COM | $5.3M | 710.9K | 0.7% | ▼−4.3% Reduced · −32K sh |
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Use Arkolith to show ESSEX INVESTMENT MANAGEMENT CO LLC's latest holdings, largest changes, and filing provenance.
As-of date vs the date the SEC received each filing
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. The performance line is a simulation of the disclosed long book, not an audited return.