Shannon River Fund Management LLC — 13F Holdings & Portfolio
CIK 1301050 · latest 13F-HR filed 2026-05-14
Shannon River Fund Management LLC manages $524.1M in 13F-reported U.S. long-equity assets across 28 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are TSEM (16.88%), MRVL (10.65%), LYV (8.57%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 13 new positions, exited 11, added to 7, and trimmed 7.
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.
$524.1M
Long-equity book
28
Distinct positions
2026-03-31
Filed 2026-05-14
+13 / −11 / ↑7 / ↓7
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- MARVELL TECHNOLOGY INC$23.7M +73.9%
- TOWER SEMICONDUCTOR LTD$17.7M +25.0%
- LIVE NATION ENTERTAINMENT IN$8.5M +23.4%
- AXON ENTERPRISE INC$8.4M +71.3%
- HINGE HEALTH INC$5.2M +48.4%
Top Trims
- ASTERA LABS INC-$22.7M -81.4%
- CELESTICA INC-$16.6M -52.4%
- GUIDEWIRE SOFTWARE INC-$15.9M -62.9%
- AMBARELLA INC-$15.4M -72.3%
- EXTREME NETWORKS-$11.9M -37.6%
New Positions
- AIRBNB INC$31.2M
- RAMBUS INC DEL$28.7M
- TOAST INC$19.4M
- ADTRAN HOLDINGS INC$15.3M
- F5 INC$14.5M
Exited Positions
- PEGASYSTEMS INC$62.0M
- UNITY SOFTWARE INC$47.1M
- CLEARWATER ANALYTICS HLDGS I$29.8M
- NCINO INC$29.1M
- KLAVIYO INC$23.7M
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 | $88.5M | 16.88% | 504,239 | SH |
| 2 | MARVELL TECHNOLOGY INC | MRVL | 573874104 | $55.8M | 10.65% | 563,573 | SH |
| 3 | LIVE NATION ENTERTAINMENT IN | LYV | 538034109 | $44.9M | 8.57% | 294,398 | SH |
| 4 | AIRBNB INC | ABNB | 009066101 | $31.2M | 5.95% | 247,006 | SH |
| 5 | RAMBUS INC DEL | RMBS | 750917106 | $28.7M | 5.48% | 333,817 | SH |
| 6 | COHERENT CORP | COHR | 19247G107 | $20.9M | 4.00% | 87,905 | SH |
| 7 | FLEXTRONICS INTL LTD | FLEX | Y2573F102 | $20.4M | 3.89% | 311,223 | SH |
| 8 | AXON ENTERPRISE INC | AXON | 05464C101 | $20.1M | 3.84% | 47,442 | SH |
| 9 | EXTREME NETWORKS | EXTR | 30226D106 | $19.8M | 3.78% | 1,313,061 | SH |
| 10 | TOAST INC | TOST | 888787108 | $19.4M | 3.70% | 732,027 | SH |
| 11 | LEGENCE CORP | LGN | 52476L109 | $19.1M | 3.64% | 337,638 | SH |
| 12 | INTERDIGITAL INC | IDCC | 45867G101 | $16.3M | 3.12% | 54,104 | SH |
| 13 | HINGE HEALTH INC | HNGE | 433313103 | $16.1M | 3.07% | 417,182 | SH |
| 14 | ADTRAN HOLDINGS INC | ADTN | 00486H105 | $15.3M | 2.93% | 1,219,976 | SH |
| 15 | CELESTICA INC | CLS | 15101Q207 | $15.1M | 2.88% | 53,495 | SH |
| 16 | F5 INC | FFIV | 315616102 | $14.5M | 2.77% | 50,196 | SH |
| 17 | LIONSGATE STUDIOS CORP | LION | 53626N102 | $10.0M | 1.90% | 1,040,934 | SH |
| 18 | GUIDEWIRE SOFTWARE INC | GWRE | 40171V100 | $9.4M | 1.79% | 62,863 | SH |
| 19 | ENERGY FUELS INC | UUUU | 292671708 | $9.3M | 1.77% | 507,555 | SH |
| 20 | SPHERE ENTERTAINMENT CO | SPHR | 55826T102 | $8.6M | 1.64% | 73,345 | SH |
| 21 | AMBARELLA INC | AMBA | G037AX101 | $5.9M | 1.13% | 114,940 | SH |
| 22 | APPLOVIN CORP | APP | 03831W108 | $5.8M | 1.10% | 14,480 | SH |
| 23 | DIGITAL RLTY TR INC | DLR | 253868103 | $5.4M | 1.03% | 29,838 | SH |
| 24 | ASTERA LABS INC | ALAB | 04626A103 | $5.2M | 0.99% | 47,394 | SH |
| 25 | OSI SYSTEMS INC | OSIS | 671044105 | $5.1M | 0.98% | 19,274 | SH |
| 26 | EQUINIX INC | EQIX | 29444U700 | $5.0M | 0.95% | 5,102 | SH |
| 27 | PALANTIR TECHNOLOGIES INC | PLTR | 69608A108 | $4.3M | 0.81% | 29,150 | SH |
| 28 | SNOWFLAKE INC | SNOW | 833445109 | $4.0M | 0.76% | 26,377 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-14 | $524.1M | 28 | 0001013594-26-000581 |
| 2025-12-31 | 2026-02-17 | $637.5M | 26 | 0001013594-26-000239 |
| 2025-09-30 | 2025-11-13 | $621.2M | 20 | 0001013594-25-001398 |