Fairmount Funds Management LLC: DIANTHUS THERAPEUTICS IN (DNTH): Quarterly 13F Position History
As of Q1 2026, Fairmount Funds Management LLC reported 2,537,191 shares of DIANTHUS THERAPEUTICS IN (DNTH), worth $212.9M and representing 15.4% of its 13F equity book. Quarter-over-quarter share count change: + 400,000 (+18.7%) . The position first appeared in Q3 2023 and has been disclosed across 11 13F-HR filings in Pactolio's tracked window.
- 2,537,191Shares Held (Latest Filing)
- $212.9MReported Market Value (Latest Filing)
- 15.4%Portfolio Weight (% of 13F Equity Book)
- +400,000Quarter-over-Quarter Share Change
- +$124.8MQuarter-over-Quarter Value Change
- 3,307,191Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 11 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 2,537,191 | +400,000 | +18.7% | $212.9M | 15.4% | $83.9 |
| Q4 2025 | 2,137,191 | 1,170,000 | -35.4% | $88.1M | 6.7% | $41.2 |
| Q3 2025 | 3,307,191 | +600,000 | +22.2% | $130.1M | 11.7% | $39.4 |
| Q2 2025 | 2,707,191 | +6,500 | +0.2% | $50.4M | 6.5% | $18.6 |
| Q1 2025 | 2,700,691 | 0 | — | $49.0M | 7.6% | $18.1 |
| Q4 2024 | 2,700,691 | 0 | — | $58.9M | 5.9% | $21.8 |
| Q3 2024 | 2,700,691 | 62,146 | -2.2% | $73.9M | 6.0% | $27.4 |
| Q2 2024 | 2,762,837 | 0 | — | $71.5M | 8.1% | $25.9 |
| Q1 2024 | 2,762,837 | +834,334 | +43.3% | $82.9M | 9.0% | $30.0 |
| Q4 2023 | 1,928,503 | 0 | — | $20.1M | 2.1% | $10.4 |
| Q3 2023 | 1,928,503 | — | — | $26.4M | 3.2% | $13.7 |
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 Fairmount Funds Management LLC first disclose a DNTH position in 13F-HR filings?
Fairmount Funds Management LLC first reported DIANTHUS THERAPEUTICS IN (DNTH) on its 13F-HR filing for the period ending 2023-09-30 (Q3 2023). The position has appeared on 11 reported quarters within Pactolio's tracked window.
What was Fairmount Funds Management LLC's most recent quarter-over-quarter share-count change in DNTH?
Between Q4 2025 and Q1 2026, Fairmount Funds Management LLC added 400,000 shares of DNTH (+18.7%), bringing the total reported position to 2,537,191 shares at a market value of $212.9M.
Does the implied price-per-share represent Fairmount Funds Management LLC's cost basis in DNTH?
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.