Wellington Biomedical Innovation Master Investors (Cayman) II L.P.
SEC insider (Form 3/4/5 filer). CIK 0001903360. 10% Owner at Avalyn Pharma Inc. (AVLN) and 3 other issuers. 5 reported Form 4/5 transactions since Sep 2024; latest on May 1, 2026. Located in BOSTON, MA.
Companies Wellington Biomedical Innovation Master Investors (Cayman) II L.P. has filed insider reports for
- Avalyn Pharma Inc. (AVLN): 10% Owner
- Metsera, Inc. (MTSR): 10% Owner
- Upstream Bio, Inc. (UPB): 10% Owner
- MBX Biosciences, Inc. (MBX): 10% Owner
Wellington Biomedical Innovation Master Investors (Cayman) II L.P.
CIK: 0001903360
Transaction Breakdown
Open Market Buys (P)0 (0.0%)
High conviction signal
Open Market Sales (S)0 (0.0%)
Position reduction
Option Exercises (M)0 (0.0%)
Derivative conversions
Awards (A)0 (0.0%)
Compensation grants
Other (G, F, J, C, D, …)5 (100.0%)
Gifts, tax withholding, conversions, dispositions to the issuer and other codes
Discretionary Trading P&L
Holdings
Transaction History (5 total)
- May 1, 2026AVLN
Avalyn Pharma Inc.
ConversionDirect1.3M shares- - Jan 30, 2025MTSR
Metsera, Inc.
ConversionDirect1.9M shares- - Oct 15, 2024UPB
Upstream Bio, Inc.
ConversionDirect894.7K shares- - Sep 16, 2024MBX
MBX Biosciences, Inc.
ConversionDirect1.4M shares- - Sep 16, 2024MBX
MBX Biosciences, Inc.
ConversionDirect403.8K shares-
| Type | Shares | Price | Ownership | |||
|---|---|---|---|---|---|---|
| May 1, 2026 |  AVLN Avalyn Pharma Inc. | Conversion | 1,275,486 | - | $0 | Direct |
| Jan 30, 2025 |  MTSR Metsera, Inc. | Conversion | 1,857,699 | - | - | Direct |
| Oct 15, 2024 |  UPB Upstream Bio, Inc. | Conversion | 894,733 | - | $0 | Direct |
| Sep 16, 2024 |  MBX MBX Biosciences, Inc. | Conversion | 1,386,335 | - | $0 | Direct |
| Sep 16, 2024 | MBX MBX Biosciences, Inc. | Conversion | 403,787 | - | $0 | Direct |
1-5 of 5 transactions