Position
CSS LLC/IL in Biogen Inc.
Back to the book · All holders of BIIB
Estimated mark uses implied 13F prices (value ÷ shares). Adds are treated as happening at this quarter’s mark; cuts at last quarter’s. Share jumps can be splits, not buys. This is not realized P&L.
Latest estimated mark $20K$175.99 → $183.33
| Quarter | Shares | Value | Implied px | Est. mark | Flow | Weight |
|---|---|---|---|---|---|---|
| Q4 2025 | 6.08K | $1.07M | — | — | — | 0.0% |
| Q1 2026 | 2.72K | $498.7K | $183.33 | $20K | −$591.3K | 0.0% |