Shannon River Fund Management LLC
In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 14, 2026), Shannon River Fund Management LLC reported 28 stock positions worth $524.1 million. Its top holding was Tower Semiconductor (TSEM) at 16.9% of the portfolio, followed by Marvell Technology (MRVL, 10.7%) and Live Nation Entertainment (LYV, 8.6%). Compared with Q4 2025, it opened 13 new positions, sold out of 11, added to 7 and reduced 8. The biggest buy was a new position in Airbnb Class A (ABNB) and the biggest sale an exit from Pegasystems (PEGA).
- Most Recent 13F
- Q2 2026
- Location
- NEW YORK, NY
- CIK
- 0001301050
- Portfolio Value
- $524.1M (Q1 2026)
- SEC Filing
- 0001013594-26-000581 ↗ filed May 14, 2026
Holdings Value
Holdings 28 stocks · $524.1M
| TSEM Tower Semiconductor Ltd. | 16.88% | 504,239 | $88.5M | Reduce -16.4% |
| MRVL Marvell Technology Inc. | 10.65% | 563,573 | $55.8M | Add +49.2% |
| LYV Live Nation Entertainment Inc. | 8.57% | 294,398 | $44.9M | Add +15.3% |
| ABNB Airbnb Inc. Class A | 5.95% | 247,006 | $31.2M | New |
| RMBS Rambus Inc. | 5.48% | 333,817 | $28.7M | New |
| COHR Coherent Corp. | 4.00% | 87,905 | $20.9M | Reduce -47.6% |
| FLEX Flex Ltd. filed as FLEXTRONICS INTL LTD | 3.89% | 311,223 | $20.4M | Reduce -0.7% |
| AXON Axon Enterprise Inc. | 3.84% | 47,442 | $20.1M | Add +129.0% |
| EXTR Extreme Networks Inc. | 3.78% | 1,313,061 | $19.8M | Reduce -31.1% |
| TOST Toast Inc. Class A | 3.70% | 732,027 | $19.4M | New |
| LGN Legence Corp. Class A | 3.64% | 337,638 | $19.1M | Add +0.8% |
| IDCC Interdigital Inc. | 3.12% | 54,104 | $16.3M | Add +1.1% |
| HNGE Hinge Health Inc. Class A | 3.07% | 417,182 | $16.1M | Add +78.8% |
| ADTN Adtran Holdings Inc. | 2.93% | 1,219,976 | $15.3M | New |
| CLS Celestica Inc. | 2.88% | 53,495 | $15.1M | Reduce -50.1% |
| FFIV F5 Inc. | 2.77% | 50,196 | $14.5M | New |
| LION Lionsgate Studios Corp. | 1.90% | 1,040,934 | $10.0M | New |
| GWRE Guidewire Software Inc. | 1.79% | 62,863 | $9.4M | Reduce -50.1% |
| UUUU Energy Fuels Inc. | 1.77% | 507,555 | $9.3M | New |
| SPHR Sphere Entertainment Co. | 1.64% | 73,345 | $8.6M | New |
| AMBA Ambarella Inc. | 1.13% | 114,940 | $5.9M | Reduce -61.8% |
| APP AppLovin Corp. Class A | 1.10% | 14,480 | $5.8M | New |
| DLR Digital Realty Trust Inc. | 1.03% | 29,838 | $5.4M | New |
| ALAB Astera Labs Inc. | 0.99% | 47,394 | $5.2M | Reduce -71.7% |
| OSIS Osi Systems Inc. | 0.98% | 19,274 | $5.1M | New |
| EQIX Equinix Inc. | 0.95% | 5,102 | $5.0M | New |
| PLTR Palantir Technologies Inc. Class A | 0.81% | 29,150 | $4.3M | Add +0.6% |
| SNOW Snowflake Inc. | 0.76% | 26,377 | $4.0M | New |
Portfolio Sells Q4 2025 → Q1 2026
| PEGA Pegasystems Inc. | Sold out | 0.00% | −9.73 |
| U Unity Software Inc. | Sold out | 0.00% | −7.38 |
| CWAN Clearwater Analytics HDS-A | Sold out | 0.00% | −4.68 |
| NCNO Ncino Inc. | Sold out | 0.00% | −4.57 |
| KVYO Klaviyo Inc. Class A | Sold out | 0.00% | −3.72 |
| CRDO Credo Technology Group Holdi | Sold out | 0.00% | −3.38 |
| ALAB Astera Labs Inc. | Reduce -71.7% | 0.99% | −3.38 |
| AMBA Ambarella Inc. | Reduce -61.8% | 1.13% | −2.22 |
| GWRE Guidewire Software Inc. | Reduce -50.1% | 1.79% | −2.18 |
| CLS Celestica Inc. | Reduce -50.1% | 2.88% | −2.09 |
| DOCU Docusign Inc. | Sold out | 0.00% | −1.68 |
| CCC CCC Intelligent Solutions Ho | Sold out | 0.00% | −1.34 |
| QCOM Qualcomm Inc. | Sold out | 0.00% | −1.24 |
| EXTR Extreme Networks Inc. | Reduce -31.1% | 3.78% | −1.20 |
| MU Micron Technology Inc. | Sold out | 0.00% | −0.91 |
| COHR Coherent Corp. | Reduce -47.6% | 4.00% | −0.87 |
| WIX Wix.com Ltd. | Sold out | 0.00% | −0.76 |
| FLEX Flex Ltd. | Reduce -0.7% | 3.89% | +0.92 |
| TSEM Tower Semiconductor Ltd. | Reduce -16.4% | 16.88% | +5.78 |
Portfolio Buys Q4 2025 → Q1 2026
| ABNB Airbnb Inc. Class A | New | 5.95% | +5.95 |
| MRVL Marvell Technology Inc. | Add +49.2% | 10.65% | +5.62 |
| RMBS Rambus Inc. | New | 5.48% | +5.48 |
| TOST Toast Inc. Class A | New | 3.70% | +3.70 |
| ADTN Adtran Holdings Inc. | New | 2.93% | +2.93 |
| LYV Live Nation Entertainment Inc. | Add +15.3% | 8.57% | +2.86 |
| FFIV F5 Inc. | New | 2.77% | +2.77 |
| AXON Axon Enterprise Inc. | Add +129.0% | 3.84% | +2.00 |
| LION Lionsgate Studios Corp. | New | 1.90% | +1.90 |
| UUUU Energy Fuels Inc. | New | 1.77% | +1.77 |
| SPHR Sphere Entertainment Co. | New | 1.64% | +1.64 |
| LGN Legence Corp. Class A | Add +0.8% | 3.64% | +1.38 |
| HNGE Hinge Health Inc. Class A | Add +78.8% | 3.07% | +1.37 |
| APP AppLovin Corp. Class A | New | 1.10% | +1.10 |
| DLR Digital Realty Trust Inc. | New | 1.03% | +1.03 |
| OSIS Osi Systems Inc. | New | 0.98% | +0.98 |
| EQIX Equinix Inc. | New | 0.95% | +0.95 |
| SNOW Snowflake Inc. | New | 0.76% | +0.76 |
| IDCC Interdigital Inc. | Add +1.1% | 3.12% | +0.45 |
| PLTR Palantir Technologies Inc. Class A | Add +0.6% | 0.81% | +0.01 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 37 | $1.1B | TSEM, FLEX, AMD, IDCC, CLS |
| Q1 2026 | 28 | $524.1M | TSEM, MRVL, LYV, ABNB, RMBS |
| Q4 2025 | 26 | $637.5M | TSEM, PEGA, U, LYV, MRVL |
| Q3 2025 | 20 | $621.2M | PEGA, TSEM, IDCC, WIX, FLEX |
| Q2 2025 | 22 | $649.3M | PEGA, FLEX, TSEM, MRVL, IDCC |
| Q1 2025 | 14 | $383.2M | IDCC, PEGA, TSEM, CWAN, FLEX |
| Q4 2024 | 17 | $565.7M | PEGA, IDCC, MRVL, WIX LTD (WIX 0 08/15/25), TSEM |
| Q3 2024 | 18 | $661.7M | IDCC, CWAN, TSEM, PEGA, MRVL |
| Q2 2024 | 21 | $581.4M | TSEM, CGNX, IDCC, NVDA, WIX |
| Q1 2024 | 18 | $449.1M | TSEM, WIX, CGNX, NVDA, IDCC |