CIK: 0000201772
Total reported value
$631.7M
Reporting period: 2026-03-31 · Number of holdings: 305
ESSEX INVESTMENT MANAGEMENT CO LLC disclosed 305 holdings in its latest 13F filing for the period ending 2026-03-31, with total reported value of $631.7M and a quarterly turnover rate of 37.7%.
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Essex Investment Management Co LLC's disclosed holdings carry a Herfindahl concentration index of 0.010 — mathematically equivalent to about 103 equally-sized positions, well below its 305 actual disclosed holdings. That gap points to a strategy built around a small core of high-conviction bets rather than broad diversification.
Position sizes vary widely across the portfolio (a coefficient of variation of 1.40), with a handful of outsized bets alongside many smaller positions.
No strong tilt toward either adding to existing winners or initiating outsized new positions was observed in the latest reported quarter.
Sector classification currently covers about 44% of this portfolio's disclosed value; the remainder includes holdings (e.g. unmapped tickers, options, or other security types) not yet covered by our sector mapping.
Add LINC
-8.6% $5.1M
Add AMPX
-13.8% $3.4M
Add DRS
+1.8% $2.9M
Trim ADPT
-21.0% -$3.3M
Trim KTOS
-16.5% -$3.2M
Add BVS
+55.5% $2.6M
Showing top 200 holdings (of 305 total)
| # | Ticker | Issuer | Asset Subclass | Weight | Weight Change | Shares Change | 4Q Trend |
|---|---|---|---|---|---|---|---|
| 1 | TSEM | Tower Semiconductor Ltd. | Stock-Tech | 3.22% | -0.23% | -39.82% | |
| 2 | LINC | Lincoln Educational Services | Stock-Other | 2.29% | +0.86% | -8.62% | |
| 3 | STRL | Sterling Infrastructure INC | Stock-Industrials | 2.07% | — | -28.26% | |
| 4 | KNSA | Kiniksa Pharmaceuticals International, plc | Stock-Other | 1.90% | — | -0.68% | |
| 5 | LGND | Ligand Pharmaceuticals | Stock-Healthcare | 1.85% | — | -2.60% | |
| 6 | DRS | Leonardo Drs INC | Stock-Industrials | 1.84% | +0.51% | +1.79% | |
| 7 | KTOS | Kratos Defense & Security | Stock-Industrials | 1.77% | -0.43% | -16.48% | |
| 8 | GSAT | Globalstar INC | Stock-Other | 1.74% | — | -1.03% | |
| 9 | INSM | Insmed INC | Stock-Healthcare | 1.62% | — | +0.41% | |
| 10 | GHM | Graham CORP | Stock-Other | 1.60% | — | -8.81% | |
| 11 | MIRM | Mirum Pharmaceuticals INC | Stock-Other | 1.58% | — | -2.67% | |
| 12 | CECO | Ceco Environmental CORP | Stock-Other | 1.48% | — | +1.81% | |
| 13 | HCI | Hci Group INC | Stock-Other | 1.41% | -0.32% | -2.66% | |
| 14 | AGX | Argan INC | Stock-Industrials | 1.39% | — | -41.73% | |
| 15 | AAPL | Apple INC | Stock-Tech | 1.31% | — | -6.56% | |
| 16 | BWAY | Brainsway Ltd-adr | Stock-Other | 1.30% | +0.42% | +103.35% | |
| 17 | AEM | Agnico Eagle Mines LTD | Stock-Materials | 1.24% | — | -3.45% | |
| 18 | AMSC | American Superconductor CORP | Stock-Other | 1.22% | — | +5.77% | |
| 19 | AMPX | Amprius Technologies INC | Stock-Other | 1.19% | +0.57% | -13.80% | |
| 20 | GEV | GE Vernova INC | Stock-Industrials | 1.15% | — | -3.30% | |
| 21 | PRIM | Primoris Services CORP | Stock-Industrials | 1.09% | — | -5.50% | |
| 22 | ADPT | Adaptive Biotechnologies | Stock-Other | 1.08% | -0.47% | -20.96% | |
| 23 | TTI | Tetra Technologies INC | Stock-Other | 1.04% | — | +1.80% | |
| 24 | GS | Goldman Sachs Group INC | Stock-Financials | 1.01% | — | -12.74% | |
| 25 | WLDN | Willdan Group INC | Stock-Other | 0.95% | -0.27% | +1.78% | |
| 26 | COHU | Cohu INC | Stock-Other | 0.93% | — | +1.78% | |
| 27 | MSFT | Microsoft CORP | Stock-Tech | 0.93% | -0.37% | -10.34% | |
| 28 | MIR | Mirion Technologies INC | Stock-Industrials | 0.91% | — | +1.90% | |
| 29 | AMZN | Amazon.com INC | Stock-Consumer Disc | 0.90% | — | -5.64% | |
| 30 | OII | Oceaneering Intl INC | Stock-Energy | 0.89% | +0.32% | +1.89% | |
| 31 | WMS | Advanced Drainage Systems In | Stock-Industrials | 0.88% | — | -5.29% | |
| 32 | BVS | Bioventus INC - A | Stock-Other | 0.87% | +0.43% | +55.52% | |
| 33 | MAMA | Mama's Creations INC | Stock-Other | 0.83% | — | +1.80% | |
| 34 | BWXT | Bwx Technologies INC | Stock-Industrials | 0.83% | — | -6.21% | |
| 35 | PATK | Patrick Industries INC | Stock-Consumer Disc | 0.81% | — | +0.62% | |
| 36 | LYTS | Lsi Industries INC | Stock-Other | 0.81% | — | +1.80% | |
| 37 | ORN | Orion Group Holdings INC | Stock-Other | 0.80% | — | +2.67% | |
| 38 | NVCR | NovoCure Limited | Stock-Healthcare | 0.78% | +0.78% | NEW | |
| 39 | TVTX | Travere Therapeutics INC | Stock-Other | 0.76% | — | +1.89% | |
| 40 | AIP | Arteris INC | Stock-Other | 0.76% | — | +1.81% | |
| 41 | AVPT | Avepoint INC | Stock-Other | 0.75% | -0.33% | -1.88% | |
| 42 | ASML | ASML Holding N.V. | Stock-Tech | 0.74% | — | -6.57% | |
| 43 | SNDX | Syndax Pharmaceuticals INC | Stock-Other | 0.74% | +0.74% | NEW | |
| 44 | CXDO | Crexendo INC | Stock-Other | 0.73% | — | +1.80% | |
| 45 | ECG | Everus Construction Group | Stock-Industrials | 0.71% | — | +1.89% | |
| 46 | XERS | Xeris Biopharma Holdings INC | Stock-Other | 0.69% | — | +1.80% | |
| 47 | GMED | Globus Medical INC - A | Stock-Healthcare | 0.68% | — | -2.73% | |
| 48 | AMBA | Ambarella, Inc. | Stock-Tech | 0.67% | — | -1.74% | |
| 49 | XZO | Exzeo Group INC | Stock-Other | 0.67% | -0.41% | -1.02% | |
| 50 | FEIM | Frequency Electronics INC | Stock-Other | 0.65% | — | +1.80% |
Performance for Q3 2026
+5.2%
Performance Last 4 Quarters
+32.3%
Based on 79% of reported portfolio value with available pricing
| Period | Holdings | Total value | Stability | Top holdings |
|---|---|---|---|---|
| 2026-03-31 | 305 | $631.7M | 38 | |
| 2025-12-31 | 306 | $655.9M | 35 | |
| 2025-09-30 | 299 | $653.4M | 67 | |
| 2025-06-30 | 298 | $550.0M | 0 | |
| 2025-03-31 | 303 | $479.4M | 100 | |
| 2024-12-31 | 307 | $556.1M | 0 | |
| 2024-09-30 | 302 | $573.7M | 0 | |
| 2024-06-30 | 302 | $534.7M | 0 | |
| 2024-03-31 | 306 | $506.7M | 0 | |
| 2023-12-31 | 315 | $507.9M | 0 | |
| 2023-09-30 | 356 | $612.7M | 0 | |
| 2023-06-30 | 369 | $716.2M | 0 | |
| 2023-03-31 | 386 | $688.0M | 0 | |
| 2022-12-31 | 395 | $641.9M | 0 | |
| 2022-09-30 | 411 | $626.5M | 0 | |
| 2022-06-30 | 423 | $619.0M | 0 | |
| 2022-03-31 | 391 | $802.4M | 0 | |
| 2021-12-31 | 405 | $873.3M | 0 | |
| 2021-09-30 | 419 | $815.2M | 0 | |
| 2021-06-30 | 419 | $860.0M | 100 | |
| 2021-03-31 | 445 | $820.0M | 46 | |
| 2020-12-31 | 481 | $805.5M | 49 | |
| 2020-09-30 | 480 | $698.7M | 42 | |
| 2020-06-30 | 423 | $610.0M | 51 | |
| 2020-03-31 | 393 | $493.9M | 75 | |
| 2019-12-31 | 475 | $813.2M | 50 | |
| 2019-09-30 | 468 | $692.8M | 48 | |
| 2019-06-30 | 477 | $728.6M | 49 | |
| 2019-03-31 | 481 | $677.0M | 48 | |
| 2018-12-31 | 476 | $637.1M | 67 | |
| 2018-09-30 | 398 | $850.9M | 38 | |
| 2018-06-30 | 396 | $798.9M | 36 | |
| 2018-03-31 | 367 | $760.5M | 31 | |
| 2017-12-31 | 355 | $758.3M | 35 | |
| 2017-09-30 | 353 | $735.8M | 38 | |
| 2017-06-30 | 340 | $698.7M | 36 | |
| 2017-03-31 | 346 | $638.2M | 42 | |
| 2016-12-31 | 339 | $607.2M | 52 | |
| 2016-09-30 | 331 | $620.9M | 53 | |
| 2016-06-30 | 314 | $600.7M | 48 | |
| 2016-03-31 | 312 | $583.6M | 43 | |
| 2015-12-31 | 309 | $639.8M | 45 | |
| 2015-09-30 | 318 | $608.9M | 41 | |
| 2015-06-30 | 312 | $662.2M | 48 | |
| 2015-03-31 | 316 | $714.7M | 46 | |
| 2014-12-31 | 332 | $686.7M | 38 | |
| 2014-09-30 | 355 | $653.5M | 49 | |
| 2014-06-30 | 354 | $678.9M | 52 | |
| 2014-03-31 | 344 | $686.8M | 46 | |
| 2013-12-31 | 360 | $707.4M | 69 | |
| 2013-09-30 | 356 | $659.7M | 57 | |
| 2013-06-30 | 333 | $566.8M | — |
Essex Investment Management Co LLC's most significant position changes for 2026-03-31: Sold out: Beta Bionics INC (BBNX); Sold out: Universal Insurance Holdings (UVE); New buy: NovoCure Limited (NVCR); New buy: Syndax Pharmaceuticals INC (SNDX); Sold out: Angiodynamics INC (ANGO).
| # | Ticker | Issuer | Weight Change | Shares Change | Action |
|---|---|---|---|---|---|
| 1 | LINC | Lincoln Educational Services | +0.9% | -8.62% | Trim |
| 2 | AMPX | Amprius Technologies INC | +0.6% | -13.80% | Trim |
| 3 | DRS | Leonardo Drs INC | +0.5% | +1.79% | Add |
| 4 | BVS | Bioventus INC - A | +0.4% | +55.52% | Add |
| 5 | BWAY | Brainsway Ltd-adr | +0.4% | +103.35% | Add |
| 6 | OII | Oceaneering Intl INC | +0.3% | +1.89% | Add |
| 7 | CODA | Coda Octopus Group INC | +0.3% | +713.94% | Add |
| 8 | RPID | Rapid Micro Biosystems Inc-a | +0.3% | +1318.24% | Add |
| 9 | LPTH | Lightpath Technologies Inc-a | +0.3% | +429.33% | Add |
| 10 | TSEM | Tower Semiconductor Ltd. | -0.2% | -39.82% | Trim |
| 11 | CRM | Salesforce INC | -0.2% | -6.43% | Trim |
| 12 | WLDN | Willdan Group INC | -0.3% | +1.78% | Add |
| 13 | LAW | Cs Disco INC | -0.3% | +1.80% | Add |
| 14 | HCI | Hci Group INC | -0.3% | -2.66% | Trim |
| 15 | AVPT | Avepoint INC | -0.3% | -1.88% | Trim |
| 16 | MSFT | Microsoft CORP | -0.4% | -10.34% | Trim |
| 17 | XZO | Exzeo Group INC | -0.4% | -1.02% | Trim |
| 18 | EVER | Everquote INC - Class A | -0.4% | -6.20% | Trim |
| 19 | KTOS | Kratos Defense & Security | -0.4% | -16.48% | Trim |
| 20 | ADPT | Adaptive Biotechnologies | -0.5% | -20.96% | Trim |
| 21 | BBNX | Beta Bionics INC | — | EXIT | Sold out |
| 22 | UVE | Universal Insurance Holdings | — | EXIT | Sold out |
| 23 | NVCR | NovoCure Limited | — | NEW | New buy |
| 24 | SNDX | Syndax Pharmaceuticals INC | — | NEW | New buy |
| 25 | ANGO | Angiodynamics INC | — | EXIT | Sold out |
| 26 | WGO | Winnebago Industries | — | EXIT | Sold out |
| 27 | MXL | Maxlinear INC | — | EXIT | Sold out |
| 28 | MG | Mistras Group INC | — | NEW | New buy |
| 29 | GLDD | Great Lakes Dredge & Dock Co | — | EXIT | Sold out |
| 30 | MITK | Mitek Systems INC | — | NEW | New buy |
| 31 | MRVL | Marvell Technology INC | — | NEW | New buy |
| 32 | AGIO | Agios Pharmaceuticals INC | — | NEW | New buy |
| 33 | SOPH | SOPHiA GENETICS SA | — | NEW | New buy |
| 34 | DIOD | Diodes INC | — | NEW | New buy |
| 35 | APYX | Apyx Medical CORP | — | NEW | New buy |
| 36 | RSKD | Riskified Ltd. | — | NEW | New buy |
| 37 | ✓ | Radcom LTD | — | EXIT | Sold out |
| 38 | LQDA | Liquidia CORP | — | NEW | New buy |
| 39 | JOUT | Johnson Outdoors Inc-a | — | NEW | New buy |
| 40 | CRNT | Ceragon Networks Ltd. | — | EXIT | Sold out |
| 41 | DERM | Journey Medical CORP | — | EXIT | Sold out |
| 42 | LZ | Legalzoomcom INC | — | EXIT | Sold out |
| 43 | PROF | Profound Medical CORP | — | EXIT | Sold out |
| 44 | FSLR | First Solar INC | — | EXIT | Sold out |
| 45 | ✓ | Infineon Technologies AG | — | EXIT | Sold out |
| 46 | BDSX | Biodesix INC | — | NEW | New buy |
| 47 | ✓ | — | EXIT | Sold out | |
| 48 | LGCY | Legacy Education INC | — | NEW | New buy |
| 49 | LTRX | Lantronix INC | — | NEW | New buy |
| 50 | PHR | Phreesia INC | — | EXIT | Sold out |
| Period | Filed | Type | EDGAR |
|---|---|---|---|
| 2026-03-31 | 2026-05-11 | 13F-HR | View on EDGAR |
| 2025-12-31 | 2026-02-13 | 13F-HR | View on EDGAR |
| 2025-09-30 | 2025-11-06 | 13F-HR | View on EDGAR |
| 2025-06-30 | 2025-08-12 | 13F-HR | View on EDGAR |
| 2025-03-31 | 2025-05-07 | 13F-HR | View on EDGAR |
| 2024-12-31 | 2025-02-07 | 13F-HR | View on EDGAR |
| 2024-09-30 | 2024-10-10 | 13F-HR | View on EDGAR |
| 2024-06-30 | 2024-08-12 | 13F-HR | View on EDGAR |
| 2024-03-31 | 2024-05-03 | 13F-HR | View on EDGAR |
| 2023-12-31 | 2024-02-08 | 13F-HR | View on EDGAR |
| 2023-09-30 | 2023-11-09 | 13F-HR | View on EDGAR |
| 2023-06-30 | 2023-08-14 | 13F-HR | View on EDGAR |
| 2023-03-31 | 2023-05-04 | 13F-HR | View on EDGAR |
| 2022-12-31 | 2023-02-03 | 13F-HR | View on EDGAR |
| 2022-09-30 | 2022-11-14 | 13F-HR | View on EDGAR |
| 2022-06-30 | 2022-08-12 | 13F-HR | View on EDGAR |
| 2022-03-31 | 2022-05-09 | 13F-HR | View on EDGAR |
| 2021-12-31 | 2022-02-10 | 13F-HR | View on EDGAR |
| 2021-09-30 | 2021-11-09 | 13F-HR | View on EDGAR |
| 2021-06-30 | 2021-08-12 | 13F-HR | View on EDGAR |
| 2021-03-31 | 2021-05-12 | 13F-HR | View on EDGAR |
| 2020-12-31 | 2021-02-12 | 13F-HR | View on EDGAR |
| 2020-09-30 | 2020-11-12 | 13F-HR | View on EDGAR |
| 2020-06-30 | 2020-08-04 | 13F-HR | View on EDGAR |
| 2020-03-31 | 2020-05-04 | 13F-HR | View on EDGAR |
| 2019-12-31 | 2020-02-10 | 13F-HR | View on EDGAR |
| 2019-09-30 | 2019-10-22 | 13F-HR | View on EDGAR |
| 2019-06-30 | 2019-08-15 | 13F-HR | View on EDGAR |
| 2019-03-31 | 2019-05-15 | 13F-HR | View on EDGAR |
| 2018-12-31 | 2019-02-07 | Amendment | View on EDGAR |
| 2018-12-31 | 2019-02-06 | 13F-HR | View on EDGAR |
| 2018-09-30 | 2018-10-16 | 13F-HR | View on EDGAR |
| 2018-06-30 | 2018-07-17 | 13F-HR | View on EDGAR |
| 2018-03-31 | 2018-04-26 | 13F-HR | View on EDGAR |
| 2017-12-31 | 2018-02-05 | 13F-HR | View on EDGAR |
| 2017-09-30 | 2017-10-30 | 13F-HR | View on EDGAR |
| 2017-06-30 | 2017-07-28 | 13F-HR | View on EDGAR |
| 2017-03-31 | 2017-04-27 | 13F-HR | View on EDGAR |
| 2016-12-31 | 2017-02-08 | 13F-HR | View on EDGAR |
| 2016-09-30 | 2016-11-01 | 13F-HR | View on EDGAR |
| 2016-06-30 | 2016-07-27 | 13F-HR | View on EDGAR |
| 2016-03-31 | 2016-05-09 | 13F-HR | View on EDGAR |
| 2015-12-31 | 2016-01-26 | 13F-HR | View on EDGAR |
| 2015-09-30 | 2015-11-04 | 13F-HR | View on EDGAR |
| 2015-06-30 | 2015-07-28 | 13F-HR | View on EDGAR |
| 2015-03-31 | 2015-05-06 | 13F-HR | View on EDGAR |
| 2014-12-31 | 2015-01-27 | 13F-HR | View on EDGAR |
| 2014-09-30 | 2014-10-29 | 13F-HR | View on EDGAR |
| 2014-06-30 | 2014-07-23 | 13F-HR | View on EDGAR |
| 2014-03-31 | 2014-04-28 | 13F-HR | View on EDGAR |
| 2013-12-31 | 2014-01-28 | 13F-HR | View on EDGAR |
| 2013-09-30 | 2013-10-25 | 13F-HR | View on EDGAR |
| 2013-06-30 | 2013-08-14 | 13F-HR | View on EDGAR |
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