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QUMSU QUANTUMSPHERE ACQUISITION CO

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UNIT 07/30/2030 (unit), issuer CIK 2070900

29 managers (30 13F filers) reported a position in QUMSU shares at 2025-09-30, 5,598,407 shares in all. 29 filers opened a position and 0 filers sold out during the quarter.

Managers
29
13F filers
30
New
29
Added
0
Reduced
0
Sold out
0
Shares held by filers
5,598,407

Shares held by filers adds up every 13F filer's report, so a share reported by a parent and by its subsidiary counts twice (H9). Managers counts each filer group once.

13D and 13G filers

No 13D or 13G on this security in the data. Structured 13D/G data starts 2024-12-18.

Insider trades

No Form 4 transaction on this security in the data.

13F holders, Q3 2025

Filers in the available 13F reports with a share position at 2025-09-30, filer groups collapsed to one row (method), largest first. Options and principal amounts are left out. A group row states no % of portfolio, since each member reports its own portfolio: the members' percents are listed under it. A value about 1,000 times or 1/1,000 of the price other filers imply is shown as filed but neither ranks the row nor enters a sum.

HolderSharesValue% of portfolioChangeSource
RIVERNORTH CAPITAL MANAGEMENT, LLC425,000$4.31M0.25%new13F-HRTimeline
GLAZER CAPITAL, LLCin group GLAZER CAPITAL, LLC420,542$4.26M0.14%new13F-HRTimelineGroup
Harraden Circle Investments, LLCin group Harraden Circle Investments, …400,707$4.06M0.79%new13F-HRTimelineGroup
Linden Advisors LPin group Linden Advisors LP400,000$4.05M0.03%new13F-HRTimelineGroup
Polar Asset Management Partners Inc.400,000$4.05M0.08%new13F-HR/ATimeline
TORONTO DOMINION BANKin group TORONTO DOMINION BANK361,000$3.66M0.01%new13F-HRTimelineGroup
AQR Arbitrage LLCin group AQR CAPITAL MANAGEMENT LLC322,660$3.27M0.08%new13F-HRTimelineGroup
HGC Investment Management Inc.300,000$3.04M0.74%new13F-HRTimeline
Meteora Capital, LLC229,999$2.33M0.25%new13F-HRTimeline
TWO SIGMA INVESTMENTS, LPin group TWO SIGMA INVESTMENTS, LP222,490$2.25M<0.01%new13F-HRTimelineGroup
Clear Street Group Inc.in group Clear Street Group Inc.218,057$2.21M0.01%13F-HRTimelineGroup
Cable Car Capital, LP174,801$1.77M0.76%new13F-HRTimeline
StoneX Group Inc.in group StoneX Group Inc.168,149$1.7M0.07%new13F-HRTimelineGroup
HEIGHTS CAPITAL MANAGEMENT, INCin group HEIGHTS CAPITAL MANAGEMENT, I…150,000$1.52M0.48%new13F-HR/ATimelineGroup
Radcliffe Capital Management, L.P.150,000$1.52M0.09%new13F-HRTimeline
WOLVERINE ASSET MANAGEMENT LLCin group WOLVERINE ASSET MANAGEMENT LLC150,000$1.52M0.02%new13F-HRTimelineGroup
BERKLEY W R CORP148,770$1.51M0.1%new13F-HRTimeline
D. E. Shaw & Co., Inc.in group D. E. Shaw & Co., Inc.125,000$1.27M<0.01%new13F-HRTimelineGroup
Periscope Capital Inc.125,000$1.27M0.31%new13F-HRTimeline
GAMCO Investors (Gabelli)group of 2 filers holding125,000$1.27MnewTimeline
BNP PARIBAS FINANCIAL MARKETSin group BNP PARIBAS FINANCIAL MARKETS102,340$1.04M<0.01%new13F-HRTimelineGroup
Westchester Capital Management, LLCin group Westchester Capital Managemen…100,000$1.01M0.05%new13F-HRTimelineGroup
BOOTHBAY FUND MANAGEMENT, LLC100,000$1.01M0.03%new13F-HRTimeline
ATW SPAC MANAGEMENT LLC100,000$1.01M1.28%new13F-HRTimeline
Schonfeld Strategic Advisors LLC87,486$886K0.01%new13F-HRTimeline
Warberg Asset Management LLC41,421$420K0.12%new13F-HRTimeline
HRT FINANCIAL LP29,985$303K<0.01%new13F-HRTimeline
JPMORGAN CHASE & COin group JPMORGAN CHASE & CO10,000$101K<0.01%new13F-HR/ATimelineGroup
TrueMark Investments, LLCin group TrueMark Investments, LLC10,000$101K0.02%new13F-HRTimelineGroup