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 Q2	$11.2M	Buy	+1,020,120	New	+$9.79M	0.42%	73
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

Alyeska Investment Group Chicago, Illinois $38.9B AUM 28.51% 1-Year Est. Return

TSC

Two Seas Capital Rye, New York $5.05B AUM 164.99% 1-Year Est. Return

OCM

Oaktree Capital Management Los Angeles, California $7.21B AUM 45.97% 1-Year Est. Return

Neuberger Berman Group New York $150B AUM 40.08% 1-Year Est. Return

ACM

Ashford Capital Management Wilmington, Delaware $933M AUM 56.2% 1-Year Est. Return

Marshall Wace London, United Kingdom $127B AUM 46.06% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

MHP

Manatuck Hill Partners Westport, Connecticut $302M AUM 117.41% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

CCM

Cinctive Capital Management New York $2.72B AUM 43.27% 1-Year Est. Return

Portolan Capital Management's QMCO Position: Q2 2026 in Review

Portolan Capital Management opened a new position in Quantum Corp (QMCO) in Q2 2026: 1,020,120 shares worth $11.2M. The stake represents 0.42% of the portfolio and ranks #73 among its holdings. This is a return to the name: Portolan Capital Management previously reported a position in QMCO as recently as Q4 2025.

Portolan Capital Management first reported a position in QMCO in Q4 2017 and has held it in 12 quarters since. 60 funds tracked by Wall St. Rank hold QMCO as of Q2 2026.

Portolan Capital Management held 1,020,120 shares of Quantum Corp worth $11.2M as of Q2 2026.
Quantum Corp was a new Portolan Capital Management position in Q2 2026.
Quantum Corp made up 0.42% of Portolan Capital Management's portfolio in Q2 2026, its #73 holding.
Portolan Capital Management first reported a position in Quantum Corp in Q4 2017 and has held it in 12 quarters since.
60 funds tracked by Wall St. Rank held Quantum Corp as of Q2 2026.

Based on Portolan Capital Management's 13F filing for Q2 2026, filed 14 Aug 2026.