DEERFIELD MANAGEMENT COMPANY, L.P. — ZENAS BIOPHARMA INC UNKNOWN: Quarterly 13F Position History
DEERFIELD MANAGEMENT COMPANY, L.P. has reported ZENAS BIOPHARMA INC (UNKNOWN) on 40 13F-HR filings in Pactolio's tracked window, first appearing in Q2 2016. As of Q1 2026, the position is sized at 839,854,000 shares ($1.21B market value, 14.26% of the equity book). Quarter-over-quarter share count change: + 265,000,000 (+46.1%) .
- 839,854,000Shares Held (Latest Filing)
- $1.21BReported Market Value (Latest Filing)
- 14.26%Portfolio Weight (% of 13F Equity Book)
- +265,000,000Quarter-over-Quarter Share Change
- +$376.6MQuarter-over-Quarter Value Change
- 1,350,219,987Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 40 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 839,854,000 | +265,000,000 | +46.1% | $1.21B | 14.26% | $1.44 |
| Q4 2025 | 574,854,000 | +265,390,892 | +85.8% | $832.3M | 10.67% | $1.45 |
| Q3 2025 | 309,463,108 | 152,895,000 | -33.1% | $383.5M | 5.88% | $1.24 |
| Q2 2025 | 462,358,108 | +65,000,000 | +16.4% | $548.9M | 9.96% | $1.19 |
| Q1 2025 | 397,358,108 | 8,459,664 | -2.1% | $458.9M | 9.10% | $1.15 |
| Q4 2024 | 405,817,772 | 58,728,479 | -12.6% | $443.3M | 8.43% | $1.09 |
| Q3 2024 | 464,546,251 | +212,684,124 | +84.4% | $497.7M | 7.44% | $1.07 |
| Q2 2024 | 251,862,127 | +140,852,455 | +126.9% | $269.1M | 4.48% | $1.07 |
| Q1 2024 | 111,009,672 | 268,680,882 | -70.8% | $105.5M | 1.83% | $0.95 |
| Q4 2023 | 379,690,554 | 240,533,446 | -38.8% | $593.7M | 10.96% | $1.56 |
| Q3 2023 | 620,224,000 | 159,036,978 | -20.4% | $787.5M | 17.35% | $1.27 |
| Q2 2023 | 779,260,978 | 153,921,041 | -16.5% | $951.1M | 20.30% | $1.22 |
| Q1 2023 | 933,182,019 | 262,296,081 | -21.9% | $1.03B | 23.00% | $1.11 |
| Q4 2022 | 1,195,478,100 | 154,741,887 | -11.5% | $1.20B | 24.85% | $1.00 |
| Q3 2022 | 1,350,219,987 | +31,169,000 | +2.4% | $1.40B | 27.91% | $1.03 |
| Q2 2022 | 1,319,050,987 | +314,838,074 | +31.4% | $1.33B | 28.02% | $1.01 |
| Q1 2022 | 1,004,212,913 | +169,320,205 | +20.3% | $1.12B | 25.12% | $1.12 |
| Q4 2021 | 834,892,708 | +150,613,318 | +22.0% | $993.8M | 20.93% | $1.19 |
| Q3 2021 | 684,279,390 | +130,927,233 | +23.7% | $892.4M | 17.45% | $1.30 |
| Q2 2021 | 553,352,157 | +236,085,408 | +74.4% | $862.2M | 15.32% | $1.56 |
| Q1 2021 | 317,266,749 | 178,407,500 | -36.0% | $505.6M | 10.62% | $1.59 |
| Q4 2020 | 495,674,249 | +85,659,635 | +20.9% | $810.9M | 16.03% | $1.64 |
| Q3 2020 | 410,014,614 | 22,990,730 | -5.3% | $652.2M | 15.88% | $1.59 |
| Q2 2020 | 433,005,344 | +29,539,269 | +7.3% | $743.9M | 21.66% | $1.72 |
| Q1 2020 | 403,466,075 | +137,627,390 | +51.8% | $543.9M | 17.26% | $1.35 |
| Q4 2019 | 265,838,685 | 38,323,383 | -12.6% | $333.9M | 10.66% | $1.26 |
| Q3 2019 | 304,162,068 | 36,282,367 | -10.7% | $307.2M | 12.55% | $1.01 |
| Q2 2019 | 340,444,435 | +29,253,552 | +9.4% | $390.5M | 14.04% | $1.15 |
| Q1 2019 | 311,190,883 | 40,989,690 | -11.6% | $345.0M | 13.23% | $1.11 |
| Q4 2018 | 352,180,573 | +29,709,462 | +9.2% | $376.5M | 15.30% | $1.07 |
| Q3 2018 | 322,471,111 | 19,855,679 | -5.8% | $403.2M | 14.68% | $1.25 |
| Q2 2018 | 342,326,790 | 33,810,534 | -9.0% | $391.5M | 13.93% | $1.14 |
| Q1 2018 | 376,137,324 | +44,336,449 | +13.4% | $443.3M | 15.73% | $1.18 |
| Q4 2017 | 331,800,875 | +19,424,005 | +6.2% | $327.2M | 12.91% | $0.99 |
| Q3 2017 | 312,376,870 | +66,989,098 | +27.3% | $332.4M | 15.02% | $1.06 |
| Q2 2017 | 245,387,772 | 119,374,475 | -32.7% | $238.9M | 13.20% | $0.97 |
| Q1 2017 | 364,762,247 | +135,985,214 | +59.4% | $410.5M | 15.94% | $1.13 |
| Q4 2016 | 228,777,033 | +21,285,547 | +10.3% | $349.8M | 14.50% | $1.53 |
| Q3 2016 | 207,491,486 | 59,643,512 | -22.3% | $434.6M | 20.21% | $2.09 |
| Q2 2016 | 267,134,998 | — | — | $574.9M | 22.59% | $2.15 |
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 DEERFIELD MANAGEMENT COMPANY, L.P. first disclose a UNKNOWN position in 13F-HR filings?
DEERFIELD MANAGEMENT COMPANY, L.P. first reported ZENAS BIOPHARMA INC (UNKNOWN) on its 13F-HR filing for the period ending 2016-06-30 (Q2 2016). The position has appeared on 40 reported quarters within Pactolio's tracked window.
What was DEERFIELD MANAGEMENT COMPANY, L.P.'s most recent quarter-over-quarter share-count change in UNKNOWN?
Between Q4 2025 and Q1 2026, DEERFIELD MANAGEMENT COMPANY, L.P. added 265,000,000 shares of UNKNOWN (+46.1%), bringing the total reported position to 839,854,000 shares at a market value of $1.21B.
Does the implied price-per-share represent DEERFIELD MANAGEMENT COMPANY, L.P.'s cost basis in UNKNOWN?
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.