Shannon River Fund Management LLC
Long book
$524.1M
Q1 2026
Positions
28
Top-10 weight
67%
concentration
Last quarter
+47.4%
SPY +14.8%
Turnover
62%
of book per quarter
Strategy in plain words
auto-generated from filingsShannon River Fund Management LLC is a concentrated fundamental stock-picker, specialised in technology (64% of the long book), running a $524.1M US long book across 28 positions.
The portfolio is concentrated: the top 10 names carry 67% of the portfolio. Turnover is high — positions rotate quickly, so individual names matter less than the process. Current anchor positions: TOWER SEMICONDUCTOR LTD, MARVELL TECHNOLOGY INC, LIVE NATION ENTERTAINMENT IN, AIRBNB INC-CLASS A, RAMBUS INC.
Over the last 9 quarters its long book ran on average 7.3pp per quarter ahead of the S&P 500, beating the index in 7 of 9 quarters. We rate its filings as signal-bearing: position changes reflect genuine views.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
+7.0%
Q2 2024
+7.6%
Q3 2024
+21.4%
Q4 2024
-19.7%
Q1 2025
+24.2%
Q2 2025
+20.0%
Q3 2025
+7.0%
Q4 2025
-8.6%
Q1 2026
+47.4%
Sector allocation
Technology 65%
Services media 18%
Industrials 8%
Other 4%
Financials 3%
Materials 2%
Long book by quarter
What does Shannon River own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| TSEM TOWER SEMICONDUCTOR LTD | Technology | 504.2K | $88.5M | 16.9% | -16.4% |
| MRVL MARVELL TECHNOLOGY INC | Technology | 563.6K | $55.8M | 10.7% | +49.2% |
| LYV LIVE NATION ENTERTAINMENT IN | Services media | 294.4K | $44.9M | 8.6% | +15.3% |
| ABNB AIRBNB INC-CLASS A | Services media | 247.0K | $31.2M | 6.0% | New |
| RMBS RAMBUS INC | Technology | 333.8K | $28.7M | 5.5% | New |
| COHR COHERENT CORP | Other | 87.9K | $20.9M | 4.0% | -47.7% |
| FLEX FLEX LTD | Technology | 311.2K | $20.4M | 3.9% | -0.7% |
| AXON AXON ENTERPRISE INC | Industrials | 47.4K | $20.1M | 3.8% | +129.0% |
| EXTR EXTREME NETWORKS INC | Technology | 1.3M | $19.8M | 3.8% | -31.1% |
| TOST TOAST INC-CLASS A | Technology | 732.0K | $19.4M | 3.7% | New |
| LGN LEGENCE CORP-CL A | Industrials | 337.6K | $19.1M | 3.6% | +0.8% |
| IDCC INTERDIGITAL INC | Financials | 54.1K | $16.3M | 3.1% | +1.1% |
| HNGE HINGE HEALTH INC-A | Technology | 417.2K | $16.1M | 3.1% | +78.8% |
| ADTN ADTRAN HOLDINGS INC | Technology | 1.2M | $15.3M | 2.9% | New |
| CLS CELESTICA INC | Technology | 53.5K | $15.1M | 2.9% | -50.1% |
| FFIV F5 INC | Technology | 50.2K | $14.5M | 2.8% | New |
| LION LIONSGATE STUDIOS CORP | Services media | 1.0M | $10.0M | 1.9% | New |
| GWRE GUIDEWIRE SOFTWARE INC | Technology | 62.9K | $9.4M | 1.8% | -50.1% |
| UUUU ENERGY FUELS INC | Materials | 507.6K | $9.3M | 1.8% | New |
| SPHR SPHERE ENTERTAINMENT CO | Services media | 73.3K | $8.6M | 1.6% | New |
| AMBA AMBARELLA INC | Technology | 114.9K | $5.9M | 1.1% | -61.8% |
| APP APPLOVIN CORP-CLASS A | Technology | 14.5K | $5.8M | 1.1% | New |
| ALAB ASTERA LABS INC | Technology | 47.4K | $5.2M | 1.0% | -71.7% |
| OSIS OSI SYSTEMS INC | Technology | 19.3K | $5.1M | 1.0% | New |
| PLTR PALANTIR TECHNOLOGIES INC-A | Technology | 29.1K | $4.3M | 0.8% | +0.6% |
| SNOW SNOWFLAKE INC | Technology | 26.4K | $4.0M | 0.8% | New |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 14, 2026 | 28 | $524.1M | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 17, 2026 | 26 | $637.5M | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 13, 2025 | 20 | $621.2M | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Aug 13, 2025 | 24 | $752.0M | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 14, 2025 | 14 | $383.2M | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 13, 2025 | 19 | $677.6M | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 13, 2024 | 19 | $714.7M | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 13, 2024 | 22 | $620.5M | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 14, 2024 | 18 | $449.1M | canonical | SEC ↗ |