Castleark Management LLC

SEC CIK: 0001106832
Latest filing: Aug 14, 2026

SEC filings (opens in a new tab)

IMGN holding history

ImmunoGen, Inc. in every 13F filed by Castleark Management LLC, including the quarters it was sold out or no filing was made. Changes compare share counts with the previous calendar quarter.

IMGN overview All 13F holders of IMGN Full Q2 2026 holdings

Shares (Q4 2023): 0; Sold out in Q4 2023
Value: $0
% of portfolio: 0.0%
Quarters held: 2; Since Q2 2023

Holdings of IMGN by Castleark Management LLC, by quarter
Quarter	Shares	Value	% of portfolio	Share change	Action	All holders
Q4 2023	0	$0	0.0%	−88,490−100.0%	Sold out	Holders
Q3 2023	88,490	$1.40M	0.1%	−970−1.1%	Reduced	Holders
Q2 2023	89,460	$1.69M	0.1%	+89,460	New	Holders