Magnetar Financial’s SiriusXM SIRI Stock Holding History

Magnetar Financial’s Portfolio SIRI Stock Details SIRI Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	–	Sell	-55,062	Closed	-$1.27M	–	1434
2026 Q1	$1.27M	Buy	+55,062	New	+$1.18M	0.01%	419
2018 Q4	–	Sell	-8,408	Closed	-$531K	–	477
2018 Q3	$531K	Sell	8,408 -1,853	-18%	-$129K	0.01%	188
2018 Q2	$695K	Buy	10,261 +4,289	+72%	+$290K	0.01%	208
2018 Q1	$373K	Sell	5,972 -32,296	-84%	-$1.94M	0.01%	398
2017 Q4	$2.05M	Buy	38,268 +24,806	+184%	+$1.37M	0.04%	114
2017 Q3	$743K	Buy	13,462 +12,309	+1,068%	+$681K	0.01%	347
2017 Q2	$63K	Sell	1,153 -30,943	-96%	-$1.58M	﹤0.01%	768
2017 Q1	$1.65M	Buy	+32,096	New	+$1.58M	0.02%	217
2016 Q1	–	Sell	-4,175	Closed	-$170K	–	449
2015 Q4	$170K	Buy	+4,175	New	+$169K	﹤0.01%	338
2014 Q2	–	Sell	-1,982,518	Closed	-$63.4M	–	230
2014 Q1	$63.4M	Buy	+1,982,518	New	+$70.1M	1.26%	23

Other funds holding SIRI

Berkshire Hathaway Omaha, Nebraska $299B AUM 27.55% 1-Year Est. Return

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

Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

KCMH

Kontiki Capital Management (HK) Hong Kong $1.52B AUM 10.48% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

CCM

Check Capital Management Costa Mesa, California $7.52B AUM 15.3% 1-Year Est. Return

Boston Partners Boston, Massachusetts $113B AUM 38.87% 1-Year Est. Return

GCM

Gates Capital Management New York $4.16B AUM 21% 1-Year Est. Return

Magnetar Financial's SIRI Position: Q2 2026 in Review

Magnetar Financial sold out of SiriusXM (SIRI) in Q2 2026, closing a stake of 55,062 shares — an estimated $1.27M sold.

Magnetar Financial first reported a position in SIRI in Q1 2014 and held it in 10 quarters. The position peaked at $63.4M in Q1 2014. 600 funds tracked by Wall St. Rank hold SIRI as of Q2 2026.

Magnetar Financial reported no remaining SiriusXM position as of Q2 2026 after selling out during the quarter.
Magnetar Financial sold 55,062 SiriusXM shares in Q2 2026, an estimated $1.27M.
Magnetar Financial first reported a position in SiriusXM in Q1 2014 and held it in 10 quarters.
Magnetar Financial's SiriusXM position peaked at $63.4M in Q1 2014.
600 funds tracked by Wall St. Rank held SiriusXM as of Q2 2026.

Based on Magnetar Financial's 13F filing for Q2 2026, filed 14 Aug 2026.