Paradigm Biocapital Advisors LP — ARCELLX INC ACLX: Quarterly 13F Position History
Paradigm Biocapital Advisors LP has reported ARCELLX INC (ACLX) on 14 13F-HR filings in Pactolio's tracked window, first appearing in Q4 2022. As of Q1 2026, the position is sized at 5,774,016 shares ($663.0M market value, 13.55% of the equity book). Quarter-over-quarter share count change: + 50,000 (+0.9%) .
- 5,774,016Shares Held (Latest Filing)
- $663.0MReported Market Value (Latest Filing)
- 13.55%Portfolio Weight (% of 13F Equity Book)
- +50,000Quarter-over-Quarter Share Change
- +$289.8MQuarter-over-Quarter Value Change
- 5,774,016Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 14 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 5,774,016 | +50,000 | +0.9% | $663.0M | 13.55% | $114.82 |
| Q4 2025 | 5,724,016 | +1,075,000 | +23.1% | $373.2M | 9.99% | $65.20 |
| Q3 2025 | 4,649,016 | 0 | — | $381.7M | 11.29% | $82.10 |
| Q2 2025 | 4,649,016 | +156,984 | +3.5% | $306.1M | 13.07% | $65.85 |
| Q1 2025 | 4,492,032 | +120,431 | +2.8% | $294.7M | 13.56% | $65.60 |
| Q4 2024 | 4,371,601 | +371,601 | +9.3% | $335.3M | 11.66% | $76.69 |
| Q3 2024 | 4,000,000 | +151,905 | +3.9% | $334.0M | 11.69% | $83.51 |
| Q2 2024 | 3,848,095 | +30,000 | +0.8% | $212.4M | 8.13% | $55.19 |
| Q1 2024 | 3,818,095 | +159,471 | +4.4% | $265.5M | 9.35% | $69.55 |
| Q4 2023 | 3,658,624 | +705,502 | +23.9% | $203.1M | 9.52% | $55.50 |
| Q3 2023 | 2,953,122 | +606,122 | +25.8% | $106.0M | 7.23% | $35.88 |
| Q2 2023 | 2,347,000 | +589,221 | +33.5% | $74.2M | 6.01% | $31.62 |
| Q1 2023 | 1,757,779 | +875,678 | +99.3% | $54.2M | 5.13% | $30.81 |
| Q4 2022 | 882,101 | — | — | $27.3M | 3.21% | $30.98 |
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 Paradigm Biocapital Advisors LP first disclose a ACLX position in 13F-HR filings?
Paradigm Biocapital Advisors LP first reported ARCELLX INC (ACLX) on its 13F-HR filing for the period ending 2022-12-31 (Q4 2022). The position has appeared on 14 reported quarters within Pactolio's tracked window.
What was Paradigm Biocapital Advisors LP's most recent quarter-over-quarter share-count change in ACLX?
Between Q4 2025 and Q1 2026, Paradigm Biocapital Advisors LP added 50,000 shares of ACLX (+0.9%), bringing the total reported position to 5,774,016 shares at a market value of $663.0M.
Does the implied price-per-share represent Paradigm Biocapital Advisors LP's cost basis in ACLX?
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.