Essex Investment Management Co. LLC
In its 13F for Q3 2025 (holdings as of September 30, 2025, filed November 6, 2025), Essex Investment Management Co. LLC reported 299 stock positions worth $653.4 million. Its top holding was Kratos Defense & Security (KTOS) at 3.4% of the portfolio, followed by Sterling Infrastructure (STRL, 2.4%) and American Superconductor (AMSC, 2.2%). Compared with Q2 2025, it opened 29 new positions, sold out of 28, added to 95 and reduced 56. The biggest buy was a new position in Globalstar (GSAT) and the biggest sale an exit from Blueprint Medicines (BPMC).
- Most Recent 13F
- Q2 2026
- Location
- BOSTON, MA
- CIK
- 0000201772
- Portfolio Value
- $653.4M (Q3 2025)
- SEC Filing
- 0000201772-25-000008 ↗ filed Nov 6, 2025
Holdings Value
Holdings 299 stocks · $653.4M
| KTOS Kratos Defense & Security | 3.41% | 244,055 | $22.3M | Reduce -30.3% |
| STRL Sterling Infrastructure Inc. | 2.37% | 45,636 | $15.5M | Reduce -14.1% |
| AMSC American Superconductor Corp. | 2.23% | 245,581 | $14.6M | Reduce -29.0% |
| TSEM Tower Semiconductor Ltd. | 2.17% | 196,339 | $14.2M | Add +0.5% |
| INSM Insmed Inc. | 1.92% | 87,077 | $12.5M | Add +31.3% |
| DRS Leonardo DRS Inc. | 1.82% | 262,550 | $11.9M | Add +3.4% |
| HCI Hci Group Inc. | 1.77% | 60,318 | $11.6M | Add +0.6% |
| LGND Ligand Pharmaceuticals | 1.66% | 61,142 | $10.8M | Add +0.6% |
| KNSA Kiniksa Pharmaceuticals Inte | 1.47% | 247,301 | $9.6M | Add +44.3% |
| ADPT Adaptive Biotechnologies | 1.46% | 638,461 | $9.6M | Add +3.4% |
| MSFT Microsoft Corp. | 1.45% | 18,265 | $9.5M | Reduce -1.2% |
| LINC Lincoln Educational Services | 1.43% | 397,359 | $9.3M | Add +3.3% |
| AAPL Apple Inc. | 1.41% | 36,260 | $9.2M | Reduce -1.1% |
| MIRM Mirum Pharmaceuticals Inc. | 1.27% | 113,458 | $8.3M | Add +0.6% |
| CECO Ceco Environmental Corp. | 1.24% | 157,980 | $8.1M | Add +3.4% |
| GHM Graham Corp. | 1.21% | 143,742 | $7.9M | Add +3.4% |
| AVPT Avepoint Inc. | 1.19% | 518,232 | $7.8M | Add +1.1% |
| AGX Argan Inc. | 1.17% | 28,298 | $7.6M | Add +3.6% |
| WLDN Willdan Group Inc. | 1.17% | 78,915 | $7.6M | Reduce -26.4% |
| PRIM Primoris Services Corp. | 1.16% | 55,123 | $7.6M | Reduce -1.3% |
| AMPX Amprius Technologies Inc. | 1.12% | 697,387 | $7.3M | Reduce -32.0% |
| MIR Mirion Technologies Inc. | 1.11% | 310,500 | $7.2M | Add +3.6% |
| GS Goldman Sachs Group Inc. | 1.10% | 8,993 | $7.2M | Reduce -1.7% |
| GSAT Globalstar Inc. | 1.08% | 194,343 | $7.1M | New |
| AMBA Ambarella Inc. | 1.08% | 85,352 | $7.0M | Add +1.0% |
| AEM Agnico Eagle Mines Ltd. | 1.05% | 40,843 | $6.9M | Reduce -1.1% |
| LYTS Lsi Industries Inc. | 0.99% | 275,147 | $6.5M | Add +3.4% |
| AMZN Amazon.com Inc. | 0.98% | 29,285 | $6.4M | Reduce -1.1% |
| XERS Xeris Biopharma Holdings Inc. | 0.93% | 750,034 | $6.1M | Add +3.3% |
| WMS Advanced Drainage Systems Inc. | 0.91% | 42,898 | $5.9M | Add +345.7% |
| GEV GE Vernova Inc. | 0.89% | 9,483 | $5.8M | Reduce -34.5% |
| EVER Everquote Inc. Class A | 0.83% | 235,782 | $5.4M | Add +0.5% |
| GWRE Guidewire Software Inc. | 0.81% | 22,901 | $5.3M | Reduce -1.6% |
| BWXT BWX Technologies Inc. | 0.78% | 27,682 | $5.1M | Reduce -1.6% |
| CLPT Clearpoint Neuro Inc. | 0.78% | 232,458 | $5.1M | Reduce -28.6% |
| OUST Ouster Inc. | 0.77% | 185,664 | $5.0M | Reduce -25.8% |
| STXS Stereotaxis Inc. | 0.76% | 1,598,114 | $5.0M | Add +3.5% |
| PATK Patrick Industries Inc. | 0.74% | 46,874 | $4.8M | Add +1.8% |
| CXDO Crexendo Inc. | 0.74% | 745,504 | $4.8M | Add +3.3% |
| UVE Universal Insurance Holdings | 0.73% | 181,244 | $4.8M | Add +3.3% |
| BWAY Brainsway Ltd.-ADR | 0.72% | 310,684 | $4.7M | Add +3.2% |
| PEGA Pegasystems Inc. | 0.71% | 80,660 | $4.6M | Reduce -1.6% |
| OCUL Ocular Therapeutix Inc. | 0.70% | 394,076 | $4.6M | Add +3.3% |
| CRM Salesforce Inc. | 0.70% | 19,422 | $4.6M | Reduce -0.4% |
| NVRI Enviri Corp. | 0.68% | 352,360 | $4.5M | Add +3.4% |
| TTI Tetra Technologies Inc. | 0.68% | 776,904 | $4.5M | Add +3.3% |
| BBNX Beta Bionics Inc. | 0.68% | 222,615 | $4.4M | New |
| PENG Penguin Solutions Inc. | 0.68% | 168,126 | $4.4M | Add +3.5% |
| MASS 908 Devices Inc. | 0.66% | 493,949 | $4.3M | Add +3.5% |
| STKL Sunopta Inc. | 0.62% | 695,206 | $4.1M | Add +2.0% |
| OII Oceaneering Intl Inc. | 0.60% | 159,261 | $3.9M | Add +58.7% |
| COHU Cohu Inc. | 0.60% | 192,846 | $3.9M | Add +31.4% |
| TVTX Travere Therapeutics Inc. | 0.59% | 161,988 | $3.9M | New |
| MXL Maxlinear Inc. | 0.59% | 240,269 | $3.9M | New |
| ASML ASML Holding NV-NY Reg SHS | 0.57% | 3,870 | $3.7M | Reduce -3.9% |
| TRMB Trimble Inc. | 0.57% | 45,669 | $3.7M | Add +168.8% |
| ZS Zscaler Inc. | 0.57% | 12,434 | $3.7M | Reduce -1.6% |
| GLDD Great Lakes Dredge & Dock Co. | 0.57% | 308,809 | $3.7M | Add +3.4% |
| ARQT Arcutis Biotherapeutics Inc. | 0.57% | 196,262 | $3.7M | Add +3.6% |
| ANGO Angiodynamics Inc. | 0.56% | 327,396 | $3.7M | Add +41.9% |
| SMTC Semtech Corp. | 0.56% | 50,946 | $3.6M | Add +3.7% |
| OSPN Onespan Inc. | 0.55% | 227,628 | $3.6M | Add +3.3% |
| GFF Griffon Corp. | 0.55% | 47,302 | $3.6M | Add +3.6% |
| MAMA Mama's Creations Inc. | 0.55% | 341,864 | $3.6M | Add +3.0% |
| SMWB Similarweb Ltd. | 0.54% | 380,793 | $3.5M | Add +45.9% |
| CON Concentra Group Holdings Par | 0.52% | 163,572 | $3.4M | Reduce -8.3% |
| RDCM Radcom Ltd. | 0.52% | 233,361 | $3.4M | Add +3.4% |
| CRNT Ceragon Networks Ltd. | 0.51% | 1,418,197 | $3.3M | Add +36.9% |
| CURI Curiositystream Inc. | 0.50% | 622,310 | $3.3M | New |
| ECG Everus Construction Group | 0.50% | 38,308 | $3.3M | Add +3.7% |
| EXTR Extreme Networks Inc. | 0.50% | 158,817 | $3.3M | Add +3.6% |
| ARLO Arlo Technologies Inc. | 0.50% | 193,267 | $3.3M | Add +3.5% |
| BGC BGC Group Inc. Class A | 0.49% | 338,489 | $3.2M | Add +3.6% |
| RDVT Red Violet Inc. | 0.49% | 61,217 | $3.2M | Add +3.4% |
| DLTR Dollar Tree Inc. | 0.49% | 33,594 | $3.2M | Reduce -2.6% |
| FEIM Frequency Electronics Inc. | 0.48% | 93,410 | $3.2M | Add +3.4% |
| SIBN Si-Bone Inc. | 0.48% | 213,385 | $3.1M | Add +3.4% |
| INFU Infusystem Holdings Inc. | 0.48% | 300,397 | $3.1M | Add +8.9% |
| ONT Onterris Inc. filed as MONTROSE ENVIRONMENTAL GROUP | 0.47% | 111,954 | $3.1M | Add +3.3% |
| PKE Park Aerospace Corp. | 0.47% | 150,434 | $3.1M | New |
| WOR Worthington Enterprises Inc. | 0.47% | 55,133 | $3.1M | New |
| EVR Evercore Inc. Class A | 0.46% | 8,958 | $3.0M | Reduce -15.2% |
| GMED Globus Medical Inc. Class A | 0.46% | 52,624 | $3.0M | Reduce -3.5% |
| LQDT Liquidity Services Inc. | 0.46% | 108,452 | $3.0M | Add +3.4% |
| DIS The Walt Disney Co. filed as DISNEY WALT CO | 0.45% | 25,958 | $3.0M | Reduce -1.9% |
| AIP Arteris Inc. | 0.45% | 292,159 | $3.0M | Add +3.6% |
| PAY Paymentus Holdings Inc. Class A | 0.45% | 95,315 | $2.9M | Add +3.6% |
| BKR Baker Hughes Co. | 0.45% | 59,827 | $2.9M | Reduce -7.9% |
| CVLG Covenant Logistics Group Inc. | 0.44% | 134,216 | $2.9M | Add +3.3% |
| LAW CS Disco Inc. | 0.44% | 443,942 | $2.9M | New |
| TRNS Transcat Inc. | 0.44% | 38,982 | $2.9M | Add +3.4% |
| LZ Legalzoomcom Inc. | 0.44% | 274,367 | $2.8M | Add +3.6% |
| DCBO Docebo Inc. | 0.43% | 103,346 | $2.8M | Add +48.3% |
| BLND Blend Labs Inc. Class A | 0.43% | 765,257 | $2.8M | Add +85.0% |
| MTRX Matrix Service Co. | 0.43% | 212,743 | $2.8M | Add +3.5% |
| BKSY Blacksky Technology Inc. | 0.42% | 136,881 | $2.8M | Add +3.5% |
| KMDA Kamada Ltd. | 0.42% | 396,434 | $2.8M | Add +22.4% |
| ASPN Aspen Aerogels Inc. | 0.42% | 390,033 | $2.7M | Reduce -8.6% |
| JAZZ Jazz Pharmaceuticals PLC | 0.41% | 20,463 | $2.7M | New |
| INTU Intuit Inc. | 0.40% | 3,814 | $2.6M | No change |
Portfolio Sells Q2 2025 → Q3 2025
| BPMC Blueprint Medicines Corp. | Sold out | 0.00% | −0.85 |
| NEE Nextera Energy Inc. | Reduce -75.4% | 0.23% | −0.78 |
| NUTX Nutex Health Inc. | Sold out | 0.00% | −0.73 |
| MRC MRC Global Inc. | Sold out | 0.00% | −0.66 |
| THC Tenet Healthcare Corp. | Sold out | 0.00% | −0.65 |
| OLO Olo Inc. Class A | Sold out | 0.00% | −0.63 |
| CGNT Cognyte Software Ltd. | Sold out | 0.00% | −0.57 |
| IEX Idex Corp. | Sold out | 0.00% | −0.57 |
| MDWD Mediwound Ltd. | Sold out | 0.00% | −0.52 |
| GEV GE Vernova Inc. | Reduce -34.5% | 0.89% | −0.50 |
| PBPB Potbelly Corp. | Sold out | 0.00% | −0.49 |
| PRCT Procept Biorobotics Corp. | Sold out | 0.00% | −0.42 |
| ULBI Ultralife Corp. | Sold out | 0.00% | −0.39 |
| ACVA Acv Auctions Inc. Class A | Sold out | 0.00% | −0.36 |
| KELYA Kelly Services Inc. Class A | Sold out | 0.00% | −0.36 |
| OUST Ouster Inc. | Reduce -25.8% | 0.77% | −0.33 |
| RSSS Research Solutions Inc. | Sold out | 0.00% | −0.31 |
| DSP Viant Technology Inc. Class A | Sold out | 0.00% | −0.29 |
| CRM Salesforce Inc. | Reduce -0.4% | 0.70% | −0.26 |
| MSFT Microsoft Corp. | Reduce -1.2% | 1.45% | −0.22 |
| SG Sweetgreen Inc. Class A | Sold out | 0.00% | −0.21 |
| AMZN Amazon.com Inc. | Reduce -1.1% | 0.98% | −0.20 |
| GWRE Guidewire Software Inc. | Reduce -1.6% | 0.81% | −0.19 |
| RRC Range Resources Corp. | Reduce -8.2% | 0.39% | −0.15 |
| ZS Zscaler Inc. | Reduce -1.6% | 0.57% | −0.15 |
| MP MP Materials Corp. | Sold out | 0.00% | −0.15 |
| CON Concentra Group Holdings Par | Reduce -8.3% | 0.52% | −0.14 |
| DIS The Walt Disney Co. | Reduce -1.9% | 0.45% | −0.14 |
| DLTR Dollar Tree Inc. | Reduce -2.6% | 0.49% | −0.14 |
| PAYX Paychex Inc. | Reduce -0.1% | 0.35% | −0.13 |
| GMED Globus Medical Inc. Class A | Reduce -3.5% | 0.46% | −0.12 |
| AVNT Avient Corp. | Reduce -95.3% | 0.00% | −0.11 |
| PEGA Pegasystems Inc. | Reduce -1.6% | 0.71% | −0.10 |
| GS Goldman Sachs Group Inc. | Reduce -1.7% | 1.10% | −0.08 |
| MYO Myomo Inc. | Sold out | 0.00% | −0.08 |
| AMSC American Superconductor Corp. | Reduce -29.0% | 2.23% | −0.08 |
| EVR Evercore Inc. Class A | Reduce -15.2% | 0.46% | −0.06 |
| WLDN Willdan Group Inc. | Reduce -26.4% | 1.17% | −0.05 |
| IWO iShares Russell 2000 Growth | Sold out | 0.00% | −0.05 |
| MTSI Macom Technology Solutions H | Reduce -8.9% | 0.09% | −0.05 |
| ASPN Aspen Aerogels Inc. | Reduce -8.6% | 0.42% | −0.04 |
| STZ Constellation Brands Inc. Class A | Reduce -88.6% | 0.00% | −0.04 |
| AXP American Express Co. | Reduce -3.0% | 0.20% | −0.04 |
| APD Air Products & Chemicals Inc. | Reduce -0.4% | 0.15% | −0.03 |
| NVMI Nova Ltd. | Reduce -60.1% | 0.02% | −0.03 |
| EFOR Everforth Inc. | Sold out | 0.00% | −0.03 |
| NVEE NV5 Global Inc. | Sold out | 0.00% | −0.02 |
| MPWR Monolithic Power Systems Inc. | Reduce -60.0% | 0.02% | −0.02 |
| PPIH Perma-Pipe International Hol | Reduce -26.4% | 0.03% | −0.02 |
| STRT Strattec Security Corp. | Reduce -23.6% | 0.04% | −0.02 |
Portfolio Buys Q2 2025 → Q3 2025
| GSAT Globalstar Inc. | New | 1.08% | +1.08 |
| WMS Advanced Drainage Systems Inc. | Add +345.7% | 0.91% | +0.71 |
| INSM Insmed Inc. | Add +31.3% | 1.92% | +0.71 |
| BBNX Beta Bionics Inc. | New | 0.68% | +0.68 |
| TSEM Tower Semiconductor Ltd. | Add +0.5% | 2.17% | +0.63 |
| KNSA Kiniksa Pharmaceuticals Inte | Add +44.3% | 1.47% | +0.61 |
| TVTX Travere Therapeutics Inc. | New | 0.59% | +0.59 |
| MXL Maxlinear Inc. | New | 0.59% | +0.59 |
| CURI Curiositystream Inc. | New | 0.50% | +0.50 |
| PKE Park Aerospace Corp. | New | 0.47% | +0.47 |
| WOR Worthington Enterprises Inc. | New | 0.47% | +0.47 |
| CECO Ceco Environmental Corp. | Add +3.4% | 1.24% | +0.45 |
| LAW CS Disco Inc. | New | 0.44% | +0.44 |
| JAZZ Jazz Pharmaceuticals PLC | New | 0.41% | +0.41 |
| LGND Ligand Pharmaceuticals | Add +0.6% | 1.66% | +0.40 |
| TRMB Trimble Inc. | Add +168.8% | 0.57% | +0.34 |
| AVD American Vanguard Corp. | New | 0.33% | +0.33 |
| XERS Xeris Biopharma Holdings Inc. | Add +3.3% | 0.93% | +0.32 |
| RAIL Freightcar America Inc. | New | 0.31% | +0.31 |
| GENC Gencor Industries Inc. | New | 0.29% | +0.29 |
| EXEL Exelixis Inc. | Add +3670.7% | 0.29% | +0.28 |
| MIRM Mirum Pharmaceuticals Inc. | Add +0.6% | 1.27% | +0.23 |
| OII Oceaneering Intl Inc. | Add +58.7% | 0.60% | +0.23 |
| TTI Tetra Technologies Inc. | Add +3.3% | 0.68% | +0.22 |
| NPCE Neuropace Inc. | Add +194.2% | 0.34% | +0.19 |
| BLND Blend Labs Inc. Class A | Add +85.0% | 0.43% | +0.18 |
| LYTS Lsi Industries Inc. | Add +3.4% | 0.99% | +0.17 |
| SMWB Similarweb Ltd. | Add +45.9% | 0.54% | +0.17 |
| STXS Stereotaxis Inc. | Add +3.5% | 0.76% | +0.17 |
| INFU Infusystem Holdings Inc. | Add +8.9% | 0.48% | +0.16 |
| PRLB Proto Labs Inc. | New | 0.16% | +0.16 |
| AEHR Aehr Test Systems | New | 0.16% | +0.16 |
| CRGO Freightos Ltd. | New | 0.16% | +0.16 |
| ADPT Adaptive Biotechnologies | Add +3.4% | 1.46% | +0.15 |
| SMTC Semtech Corp. | Add +3.7% | 0.56% | +0.15 |
| NVRI Enviri Corp. | Add +3.4% | 0.68% | +0.15 |
| ANGO Angiodynamics Inc. | Add +41.9% | 0.56% | +0.14 |
| MDT Medtronic PLC | New | 0.14% | +0.14 |
| HCI Hci Group Inc. | Add +0.6% | 1.77% | +0.11 |
| KRNT Kornit Digital Ltd. | New | 0.11% | +0.11 |
| FEIM Frequency Electronics Inc. | Add +3.4% | 0.48% | +0.11 |
| NXT Nextpower Inc. | New | 0.09% | +0.09 |
| AEVA Aeva Technologies Inc. | New | 0.09% | +0.09 |
| PENG Penguin Solutions Inc. | Add +3.5% | 0.68% | +0.09 |
| IOT Samsara Inc. Class A | Add +162.3% | 0.17% | +0.09 |
| FLNC Fluence Energy Inc. | New | 0.09% | +0.09 |
| DERM Journey Medical Corp. | Add +55.1% | 0.39% | +0.09 |
| COHU Cohu Inc. | Add +31.4% | 0.60% | +0.09 |
| ARQT Arcutis Biotherapeutics Inc. | Add +3.6% | 0.57% | +0.08 |
| ECG Everus Construction Group | Add +3.7% | 0.50% | +0.08 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 306 | $763.4M | TSEM, LINC, KNSA, OUST, LGND |
| Q1 2026 | 305 | $631.7M | TSEM, LINC, STRL, KNSA, LGND |
| Q4 2025 | 306 | $655.9M | TSEM, KTOS, STRL, HCI, LGND |
| Q3 2025 | 299 | $653.4M | KTOS, STRL, AMSC, TSEM, INSM |
| Q2 2025 | 298 | $550.0M | KTOS, AMSC, STRL, DRS, AVPT |
| Q1 2025 | 303 | $479.4M | HCI, KTOS, DRS, AAPL, NEE |
| Q4 2024 | 307 | $556.1M | PRIM, AMSC, AAPL, KTOS, HCI |
| Q3 2024 | 302 | $573.7M | AMSC, DRS, AAPL, HCI, NEE |
| Q2 2024 | 302 | $534.7M | AMSC, AAPL, MSFT, DRS, NEE |
| Q1 2024 | 306 | $506.7M | MSFT, AAPL, HCI, NEE, CRM |