Alex Keun Mo Yang - 27 May 2026 Form 4 Insider Report for Polaryx Therapeutics, Inc. (PLYX)

Reporting relationship: Chief Executive Officer, Director, 10%+ Owner
Issuer ticker: PLYX
Reported as of: 27 May 2026
Net transaction value: +$360,004
SEC form: 4
Accepted by SEC: 28 May 2026, 20:00:39 UTC
Prior SEC filing: 29 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Alex Keun Mo Yang

Key filing fact

Alex Keun Mo Yang filed Form 4 for Polaryx Therapeutics, Inc. (PLYX) on 28 May 2026.

Key facts

This page summarizes Alex Keun Mo Yang's Form 4 filing for Polaryx Therapeutics, Inc. (PLYX).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 28 May 2026, 20:00.

Change

Previous filing in this sequence was filed on 29 Jan 2026.
Current net transaction value: +$360,004.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (2)

CIK 0002103399 Primary reporting owner

Yang Alex Keun Mo

Relationship: Chief Executive Officer, Director, 10%+ Owner
Address: SOUTH TOWER, 140 E RIDGEWOOD AVENUE,, SUITE 415, PARAMUS
Signature: /s/ Alex Keun Mo Yang
Signature date: 28 May 2026

CIK 0002104809

Mstone Partners Healthcare Ltd

Relationship: Director, 10%+ Owner
Address: 7/F, 80 GLOUCESTER ROAD, WANCHAI, HONG KONG
Signature: /s/ Alex Keun Mo Yang, Chief Executive Officer of Mstone Partners Healthcare Limited.
Signature date: 28 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

PLYX transaction

Common Stock

Purchase

Transaction value: $360,004
Shares: +88,453
Change %: +0.37%
Price: $4.07
Shares after: 24,233,249
Date: 27 May 2026
Ownership: By Mstone Partners Healthcare Limited
Footnotes: F1, F2

PLYX transaction

Common Stock

Purchase

Transaction value: $360,004
Shares: +88,453
Change %: +0.37%
Price: $4.07
Shares after: 24,233,249
Date: 27 May 2026
Ownership: By Mstone Partners Healthcare Limited
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

As disclosed in the Issuer's Form 8-K filed with the Securities and Exchange Commission on May 28, 2026, MStone Partners Healthcare Limited ("Mstone") purchased 88,453 shares of common stock in a private placement transaction, for gross proceeds to the Issuer of $360,000.

Footnote F2

Alex Keun Mo Yang is the founder and Chief Executive Officer of Mstone. Mr. Yang disclaims beneficial ownership over any of the reported securities, except to the extent of his pecuniary interest therein.