Portolan Capital Management’s Quantum Corp QMCO Stock Holding History

Portolan Capital Management’s Portfolio QMCO Stock Details QMCO Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	–	Sell	-477,214	Closed	-$3.08M	–	168
2025 Q4	$3.08M	Buy	+477,214	New	+$4.28M	0.16%	125
2021 Q2	–	Sell	-23,447	Closed	-$3.91M	–	151
2021 Q1	$3.91M	Buy	23,447 +17,691	+307%	+$2.82M	0.31%	113
2020 Q4	$705K	Sell	5,756 -242	-4%	-$25.7K	0.06%	136
2020 Q3	$552K	Sell	5,998 -13,486	-69%	-$1.31M	0.06%	132
2020 Q2	$1.5M	Sell	19,484 -11,886	-38%	-$941K	0.17%	117
2020 Q1	$1.85M	Buy	+31,370	New	+$2.82M	0.28%	90
2019 Q1	–	Sell	-1,611	Closed	-$64K	–	94
2018 Q4	$64K	Sell	1,611 -146,125	-99%	-$6.71M	0.01%	82
2018 Q3	$7.09M	Buy	147,736 +43,828	+42%	+$1.79M	0.7%	50
2018 Q2	$4.57M	Sell	103,908 -30,124	-22%	-$2.02M	0.47%	69
2018 Q1	$9.76M	Buy	134,032 +79,125	+144%	+$7.7M	1.07%	34
2017 Q4	$6.18M	Buy	+54,907	New	+$5.91M	0.68%	52

Other funds holding QMCO

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

UBS Group Zurich, Switzerland $666B AUM 30.12% 1-Year Est. Return

VFT

Vanguard Fiduciary Trust Malvern, Pennsylvania $396B AUM

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

SAMU

SONA Asset Management (US) New York $4.74B AUM 11.18% 1-Year Est. Return

Marshall Wace London, United Kingdom $100B AUM 35.1% 1-Year Est. Return

Northern Trust Chicago, Illinois $757B AUM 28.64% 1-Year Est. Return

LPL Financial San Diego, California $377B AUM 19.32% 1-Year Est. Return

Portolan Capital Management's QMCO Position: Q1 2026 in Review

Portolan Capital Management sold out of Quantum Corp (QMCO) in Q1 2026, closing a stake of 477,214 shares — an estimated $3.08M sold.

Portolan Capital Management first reported a position in QMCO in Q4 2017 and held it in 11 quarters. The position peaked at $9.76M in Q1 2018. 37 funds tracked by Wall St. Rank hold QMCO as of Q1 2026.

Portolan Capital Management reported no remaining Quantum Corp position as of Q1 2026 after selling out during the quarter.
Portolan Capital Management sold 477,214 Quantum Corp shares in Q1 2026, an estimated $3.08M.
Portolan Capital Management first reported a position in Quantum Corp in Q4 2017 and held it in 11 quarters.
Portolan Capital Management's Quantum Corp position peaked at $9.76M in Q1 2018.
37 funds tracked by Wall St. Rank held Quantum Corp as of Q1 2026.

Based on Portolan Capital Management's 13F filing for Q1 2026, filed 15 May 2026.