ESSEX INVESTMENT MANAGEMENT CO LLC — 13F Holdings & Portfolio
CIK 201772 · latest 13F-HR filed 2026-08-06
ESSEX INVESTMENT MANAGEMENT CO LLC manages $763.4M in 13F-reported U.S. long-equity assets across 306 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are TSEM (3.60%), LINC (2.22%), KNSA (2.02%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 27 new positions, exited 26, added to 176, and trimmed 69.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$763.4M
Long-equity book
306
Distinct positions
2026-06-30
Filed 2026-08-06
+27 / −26 / ↑176 / ↓69
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
| Name | Title / Status | Ownership | Type |
|---|
Quarter-over-quarter changes
Share-count changes vs the prior 13F.
Top Adds (vs prior quarter)
- OUSTER INC$10.7M +316.8%
- ARTERIS INC$8.7M +182.7%
- TOWER SEMICONDUCTOR LTD$7.2M +35.2%
- CECO ENVIRONMENTAL CORP$4.3M +45.7%
- MARVELL TECHNOLOGY INC$4.1M +115.2%
Top Trims
- INSMED INC-$5.7M -55.3%
- AMPRIUS TECHNOLOGIES INC-$3.6M -47.5%
- KRATOS DEFENSE & SEC SOLUTIONS-$3.5M -31.6%
- WORKIVA INC-$2.1M -98.4%
- AGNICO EAGLE MINES LTD-$1.9M -23.9%
New Positions
- WERNER ENTERPRISES INC$10.1M
- XOMETRY INC$5.4M
- BLUELINX HLDGS INC$5.4M
- INTERFACE INC$4.4M
- PRECIGEN INC$4.0M
Exited Positions
- GLOBALSTAR INC$11.0M
- PRIMORIS SVCS CORP$6.9M
- BIOVENTUS INC$5.5M
- SYNDAX PHARMACEUTICALS INC$4.6M
- AGIOS PHARMACEUTICALS INC$3.5M
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | TOWER SEMICONDUCTOR LTD | TSEM | M87915274 | $27.5M | 3.60% | 105,543 | SH |
| 2 | LINCOLN EDL SVCS CORP | LINC | 533535100 | $17.0M | 2.22% | 340,366 | SH |
| 3 | KINIKSA PHARMACEUTICALS INTL P | KNSA | G52694109 | $15.4M | 2.02% | 241,382 | SH |
| 4 | OUSTER INC | OUST | 68989M202 | $14.1M | 1.85% | 226,028 | SH |
| 5 | LIGAND PHARMACEUTICALS INC | LGND | 53220K504 | $13.8M | 1.80% | 43,567 | SH |
| 6 | CECO ENVIRONMENTAL CORP | CECO | 125141101 | $13.6M | 1.79% | 150,416 | SH |
| 7 | STERLING INFRASTRUCTURE INC | STRL | 859241101 | $13.6M | 1.78% | 16,155 | SH |
| 8 | ARTERIS INC | AIP | 04302A104 | $13.5M | 1.77% | 277,665 | SH |
| 9 | MIRUM PHARMACEUTICALS INC | MIRM | 604749101 | $12.4M | 1.62% | 105,669 | SH |
| 10 | ARGAN INC | AGX | 04010E109 | $12.4M | 1.62% | 15,467 | SH |
| 11 | GRAHAM CORP | GHM | 384556106 | $11.6M | 1.51% | 93,405 | SH |
| 12 | LEONARDO DRS INC | DRS | 52661A108 | $10.7M | 1.40% | 250,215 | SH |
| 13 | ADAPTIVE BIOTECHNOLOGIES CORP | ADPT | 00650F109 | $10.1M | 1.33% | 472,763 | SH |
| 14 | WERNER ENTERPRISES INC | WERN | 950755108 | $10.1M | 1.32% | 231,625 | SH |
| 15 | HCI GROUP INC | HCI | 40416E103 | $9.9M | 1.29% | 56,260 | SH |
| 16 | GE VERNOVA INC | GEV | 36828A101 | $9.7M | 1.27% | 8,283 | SH |
| 17 | COHU INC | COHU | 192576106 | $9.7M | 1.27% | 131,170 | SH |
| 18 | APPLE INC | AAPL | 037833100 | $9.4M | 1.23% | 32,427 | SH |
| 19 | AMERICAN SUPERCONDUCTOR CORP | AMSC | 030111207 | $9.2M | 1.21% | 221,933 | SH |
| 20 | BRAINSWAY LTD | BWAY | 10501L106 | $9.2M | 1.20% | 592,606 | SH |
| 21 | TETRA TECHNOLOGIES INC DEL | TTI | 88162F105 | $8.4M | 1.10% | 741,007 | SH |
| 22 | LSI INDS INC OHIO | LYTS | 50216C108 | $7.9M | 1.03% | 295,820 | SH |
| 23 | MARVELL TECHNOLOGY INC | MRVL | 573874104 | $7.7M | 1.01% | 25,911 | SH |
| 24 | KRATOS DEFENSE & SEC SOLUTIONS | KTOS | 50077B207 | $7.7M | 1.00% | 153,576 | SH |
| 25 | TRAVERE THERAPEUTICS INC | TVTX | 89422G107 | $7.6M | 1.00% | 133,866 | SH |
| 26 | GOLDMAN SACHS GROUP INC | GS | 38141G104 | $7.6M | 1.00% | 7,513 | SH |
| 27 | PATRICK INDS INC | PATK | 703343103 | $7.4M | 0.98% | 82,960 | SH |
| 28 | ORION GROUP HLDGS INC | ORN | 68628V308 | $7.4M | 0.98% | 442,603 | SH |
| 29 | ASML HLDG NV | ASML | N07059210 | $7.0M | 0.92% | 3,538 | SH |
| 30 | AMBARELLA INC | AMBA | G037AX101 | $6.9M | 0.90% | 79,997 | SH |
| 31 | NOVOCURE LTD | NVCR | G6674U108 | $6.7M | 0.87% | 439,648 | SH |
| 32 | AMAZON COM INC | AMZN | 023135106 | $6.4M | 0.84% | 27,062 | SH |
| 33 | AVEPOINT INC | AVPT | 053604104 | $6.4M | 0.84% | 571,541 | SH |
| 34 | ADVANCED DRAIN SYS INC DEL | WMS | 00790R104 | $6.3M | 0.83% | 40,413 | SH |
| 35 | SEMTECH CORP | SMTC | 816850101 | $6.2M | 0.81% | 38,226 | SH |
| 36 | OCEANEERING INTL INC | OII | 675232102 | $6.1M | 0.80% | 151,463 | SH |
| 37 | EVERUS CONSTR GROUP | ECG | 300426103 | $6.0M | 0.79% | 36,377 | SH |
| 38 | AGNICO EAGLE MINES LTD | AEM | 008474108 | $6.0M | 0.78% | 38,462 | SH |
| 39 | LIQUIDIA CORPORATION | LQDA | 53635D202 | $6.0M | 0.78% | 74,743 | SH |
| 40 | WILLDAN GROUP INC | WLDN | 96924N100 | $5.9M | 0.78% | 74,890 | SH |
| 41 | FREQUENCY ELECTRS INC | FEIM | 358010106 | $5.9M | 0.77% | 89,043 | SH |
| 42 | MICROSOFT CORP | MSFT | 594918104 | $5.9M | 0.77% | 15,714 | SH |
| 43 | MAMAS CREATIONS INC | MAMA | 56146T103 | $5.8M | 0.76% | 326,938 | SH |
| 44 | XERIS BIOPHARMA HOLDINGS INC | XERS | 98422E103 | $5.7M | 0.74% | 715,608 | SH |
| 45 | PARK AEROSPACE CORP | PKE | 70014A104 | $5.5M | 0.72% | 143,663 | SH |
| 46 | BIODESIX INC | BDSX | 09075X207 | $5.5M | 0.71% | 241,915 | SH |
| 47 | XOMETRY INC | XMTR | 98423F109 | $5.4M | 0.71% | 55,919 | SH |
| 48 | BLUELINX HLDGS INC | BXC | 09624H208 | $5.4M | 0.70% | 86,593 | SH |
| 49 | MITEK SYS INC | MITK | 606710200 | $5.3M | 0.70% | 263,913 | SH |
| 50 | CREXENDO INC | CXDO | 226552107 | $5.3M | 0.70% | 710,874 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-06 | $763.4M | 306 | 0000201772-26-000005 |
| 2026-03-31 | 2026-05-11 | $631.7M | 305 | 0000201772-26-000004 |
| 2025-12-31 | 2026-02-13 | $655.9M | 306 | 0000201772-26-000001 |
| 2025-09-30 | 2025-11-06 | $653.4M | 299 | 0000201772-25-000008 |
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