Shannon River Fund Management LLC: TOWER SEMICONDUCTOR LTD (TSEM): Quarterly 13F Position History
As of Q1 2026, Shannon River Fund Management LLC reported 504,239 shares of TOWER SEMICONDUCTOR LTD (TSEM), worth $88.5M and representing 16.9% of its 13F equity book. Quarter-over-quarter share count change: 98,565 (-16.4%) . The position first appeared in Q4 2023 and has been disclosed across 10 13F-HR filings in Pactolio's tracked window.
- 504,239Shares Held (Latest Filing)
- $88.5MReported Market Value (Latest Filing)
- 16.9%Portfolio Weight (% of 13F Equity Book)
- 98,565Quarter-over-Quarter Share Change
- +$17.7MQuarter-over-Quarter Value Change
- 1,983,350Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 10 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 504,239 | 98,565 | -16.4% | $88.5M | 16.9% | $175.5 |
| Q4 2025 | 602,804 | 359,259 | -37.3% | $70.8M | 11.1% | $117.4 |
| Q3 2025 | 962,063 | 505,441 | -34.4% | $69.6M | 11.2% | $72.3 |
| Q2 2025 | 1,467,504 | +274,791 | +23.0% | $63.6M | 9.8% | $43.4 |
| Q1 2025 | 1,192,713 | +106,822 | +9.8% | $42.5M | 11.1% | $35.7 |
| Q4 2024 | 1,085,891 | 252,324 | -18.9% | $55.9M | 9.9% | $51.5 |
| Q3 2024 | 1,338,215 | 645,135 | -32.5% | $59.2M | 9.0% | $44.3 |
| Q2 2024 | 1,983,350 | +150,014 | +8.2% | $78.0M | 13.4% | $39.3 |
| Q1 2024 | 1,833,336 | +570,610 | +45.2% | $61.3M | 13.7% | $33.5 |
| Q4 2023 | 1,262,726 | — | — | $38.5M | 10.7% | $30.5 |
Methodology & FAQ
How This Position History Is Sourced
Each row is one SEC Form 13F-HR filing disclosing this position. Share count, market value, and reported quarter are taken verbatim from the filing; portfolio weight is recomputed against the same filing's total reported equity book. Implied price-per-share is market value divided by shares — a quarter-end mark, not the manager's cost basis. See the full methodology document for the normalization rules.
When did Shannon River Fund Management LLC first disclose a TSEM position in 13F-HR filings?
Shannon River Fund Management LLC first reported TOWER SEMICONDUCTOR LTD (TSEM) on its 13F-HR filing for the period ending 2023-12-31 (Q4 2023). The position has appeared on 10 reported quarters within Pactolio's tracked window.
What was Shannon River Fund Management LLC's most recent quarter-over-quarter share-count change in TSEM?
Between Q4 2025 and Q1 2026, Shannon River Fund Management LLC reduced its TSEM position by 98,565 shares (-16.4%), leaving 504,239 shares at a market value of $88.5M.
Does the implied price-per-share represent Shannon River Fund Management LLC's cost basis in TSEM?
No. The implied price-per-share column is the 13F-HR reported market value divided by reported share count on the filing date (end of quarter). It is a quarter-end mark, not a cost basis or transaction price. Use it as a sanity check on the value column, not as an indicator of the manager's entry or exit price.