683 Capital Management, LLC

Holdings History for Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN)

Symbol: MRSN
Investment type: Equity / Common Stock, par value $0.0001 per share
Latest Disclosed Shares Owned: 351,289 shares
Security Ownership %: 7%

Shares, Excluding Options vs Price

Value, Excluding Options

683 Capital Management, LLC ownership in Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN)

17 Feb 2026 - 683 Capital Management, LLC has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 351,289 shares of Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN). This represents 7% ownership of the company. In their previous filing dated 24 Nov 2025, 683 Capital Management, LLC had reported owning 273,420 shares, indicating an increase of +28%. .

Reporting Name	Ownership %	Change	Value $	Shares owned	Change	Activity %	Price	Form	Report date	Filing time
683 Capital Management, LLC	7%	+31%	$10,215,484	351,289	+77,869	+28%	$29.08	13G/A	31 Dec 2025	17 Feb 2026, 10:09
683 Capital Management, LLC	5.5%		$2,542,806	273,420			$9.30	13G	17 Nov 2025	24 Nov 2025, 17:12

Holdings date	Option	Weight	Change	Value $	Shares	Change	Activity %	Price	All Holders
31 Dec 2025			-0.07%	$0	0	-100,000	-100%	$29.08	Q4 2025
30 Sep 2025		0.07%	+0.07%	$776,000	100,000	+100,000	NEW	$7.76	Q3 2025

* Reported Price is the price of the security as of the portfolio date. This value is significant in that it is the last known price at which the security was still held.
An asterisk sign (*) next to the price indicates that the price is likely invalid.