Form
SCHEDULE 13D
Active or control-oriented beneficial ownership filing.
Madison Avenue Partners, LP - 29 Apr 2025 SCHEDULE 13D Report for ACELYRIN, Inc. Common Stock (SLRN)
- Filing manager
- Madison Avenue Partners, LP
- Reporting owner
- Madison Avenue Partners, LP
- Security
- ACELYRIN, Inc. Common Stock
- Beneficially owned shares
- 5,089,260 shares
- Large-stake signal
-
Ownership
5.1%Beneficial ownership of this reported class.
Shares
5,089,260 sharesShares beneficially owned as disclosed.
Event date
29 Apr 2025Date tied to the ownership event or amendment.
Accepted by SEC
30 Apr 2025EDGAR acceptance date.
How to read this large-stake filing
- Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
- Compare this filing with the holder history and issuer page before treating the percentage as a current position.
- Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
- Class ownership
- 5.1%
- Symbol
- SLRN
- Shares outstanding
- 99,789,412 shares
- SEC form
- SCHEDULE 13D
- Accepted by SEC
- 30 Apr 2025, 20:27:15 UTC
- Event date
- 29 Apr 2025
- Source filing
- View source filing
Ownership signal
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Subject security
Names, identifiers, and filing context for this profile.
2 source fields
Source evidence
Original filing metadata and source links for verification.
4 source fields
Key filing fact
Madison Avenue Partners, LP disclosed 5.1% ownership in ACELYRIN, Inc. Common Stock (SLRN) on 29 Apr 2025.
Key facts
- Madison Avenue Partners, LP filed SCHEDULE 13D for ACELYRIN, Inc. Common Stock (SLRN).
- Disclosed ownership: 5.1%.
- Date of event: 29 Apr 2025.
Change
- No earlier schedule filing is available for direct comparison.
- Current filing was accepted on 30 Apr 2025, 20:27.
Research use
- This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
- Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.
Evidence
Backed by Schedule 13D/13G
View source filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting persons
Disclosed reporting parties (6)
Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.
| Name | Ownership | Shares owned | Sole voting power | Shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Madison Avenue International LP | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha, as Manager of Madison Avenue GP, LLC, the General Partner of Madison Avenue International LP | |
| Madison Avenue Partners, LP | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha, as Managing Member of EMAI Management, LLC, the General Partner of Madison Avenue Partners, LP | 0001801265 |
| EMAI Management, LLC | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha, as Manager | |
| Madison Avenue GP, LLC | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha, as Member | |
| Caraway Jackson Investments LLC | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha, as Member | |
| Eli Samaha | 5.1% | 5,089,260 | 0 | 5,089,260 | /s/ Eli Samaha | Eli Samaha | 0001877589 |
CIK / CUSIP context first