Tweedy, Browne Co LLC: IONIS PHARMACEUTICALS INC (IONS): Quarterly 13F Position History
As of Q1 2026, Tweedy, Browne Co LLC reported 2,275,625 shares of IONIS PHARMACEUTICALS INC (IONS), worth $170.9M and representing 13.6% of its 13F equity book. Quarter-over-quarter share count change: 189,305 (-7.7%) . The position first appeared in Q1 2022 and has been disclosed across 17 13F-HR filings in Pactolio's tracked window.
- 2,275,625Shares Held (Latest Filing)
- $170.9MReported Market Value (Latest Filing)
- 13.6%Portfolio Weight (% of 13F Equity Book)
- 189,305Quarter-over-Quarter Share Change
- -$24.1MQuarter-over-Quarter Value Change
- 3,541,136Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 17 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 2,275,625 | 189,305 | -7.7% | $170.9M | 13.6% | $75.1 |
| Q4 2025 | 2,464,930 | 436,286 | -15.0% | $195.0M | 15.7% | $79.1 |
| Q3 2025 | 2,901,216 | +9,268 | +0.3% | $189.8M | 16.5% | $65.4 |
| Q2 2025 | 2,891,948 | 91,570 | -3.1% | $114.3M | 10.6% | $39.5 |
| Q1 2025 | 2,983,518 | 265,345 | -8.2% | $90.0M | 8.0% | $30.2 |
| Q4 2024 | 3,248,863 | 205,813 | -6.0% | $113.6M | 7.7% | $35.0 |
| Q3 2024 | 3,454,676 | 0 | — | $138.4M | 6.6% | $40.1 |
| Q2 2024 | 3,454,676 | 0 | — | $164.6M | 7.6% | $47.7 |
| Q1 2024 | 3,454,676 | 0 | — | $149.8M | 7.0% | $43.4 |
| Q4 2023 | 3,454,676 | 55,497 | -1.6% | $174.8M | 8.5% | $50.6 |
| Q3 2023 | 3,510,173 | 30,685 | -0.9% | $159.2M | 8.5% | $45.4 |
| Q2 2023 | 3,540,858 | 188 | -0.0% | $145.3M | 7.6% | $41.0 |
| Q1 2023 | 3,541,046 | 90 | -0.0% | $126.6M | 6.9% | $35.7 |
| Q4 2022 | 3,541,136 | +818,148 | +30.0% | $133.7M | 7.1% | $37.8 |
| Q3 2022 | 2,722,988 | 3,790 | -0.1% | $120.4M | 5.3% | $44.2 |
| Q2 2022 | 2,726,778 | 198,324 | -6.8% | $100.9M | 4.1% | $37.0 |
| Q1 2022 | 2,925,102 | — | — | $108.3M | 3.5% | $37.0 |
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 Tweedy, Browne Co LLC first disclose a IONS position in 13F-HR filings?
Tweedy, Browne Co LLC first reported IONIS PHARMACEUTICALS INC (IONS) on its 13F-HR filing for the period ending 2022-03-31 (Q1 2022). The position has appeared on 17 reported quarters within Pactolio's tracked window.
What was Tweedy, Browne Co LLC's most recent quarter-over-quarter share-count change in IONS?
Between Q4 2025 and Q1 2026, Tweedy, Browne Co LLC reduced its IONS position by 189,305 shares (-7.7%), leaving 2,275,625 shares at a market value of $170.9M.
Does the implied price-per-share represent Tweedy, Browne Co LLC's cost basis in IONS?
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.