On this page, we present all of the funds holding QSI from our database of 13F filers, detailed in the table below. The first column indicates the name of each of the funds holding QSI, with a link to that fund's top holdings. The next columns indicate the amount of QSI stock held by each of the funds holding QSI, followed by the QSI position size held by the fund, and lastly the date of the quarterly filing period the data represents. In total, we count 88 funds holding QSI within the last two filing periods in our coverage universe of 13F filers, with the largest position size having been reported by ARK Investment Management LLC. For more details on the positions held by ARK Investment Management LLC (or by any of the other funds holding QSI), click the fund name in the "Holder" column of the funds-holding-QSI table below.

Holder	Amount	Position Size ($ in 1000's)	As of
ARK Investment Management LLC	12,768,876	$25,155	03/31/2024
QSI	12,768,876	$25,155	03/31/2024
Nikko Asset Management Americas Inc.	8,532,917	$17,066	12/31/2023
QSI	8,532,917	$17,066	12/31/2023
Sumitomo Mitsui Trust Holdings Inc.	8,054,503	$15,867	03/31/2024
QSI	8,054,503	$15,867	03/31/2024
BlackRock Inc.	7,383,571	$14,841	12/31/2023
QSI	7,383,571	$14,841	12/31/2023
Vanguard Group Inc.	5,218,222	$10,489	12/31/2023
QSI	5,218,222	$10,489	12/31/2023
State Street Corp	2,209,837	$4,442	12/31/2023
QSI	2,209,837	$4,442	12/31/2023
Geode Capital Management LLC	2,123,452	$4,269	12/31/2023
QSI	2,123,452	$4,269	12/31/2023
Northern Trust Corp	824,387	$1,657	12/31/2023
QSI	824,387	$1,657	12/31/2023
Fosun International Ltd	743,935	$1,495	12/31/2023
QSI	743,935	$1,495	12/31/2023
Bridgeway Capital Management Inc.	406,700	$817	12/31/2023
QSI	406,700	$817	12/31/2023
Bank of New York Mellon Corp	342,382	$688	12/31/2023
QSI	342,382	$688	12/31/2023
Knollwood Investment Advisory LLC	300,000	$603	12/31/2023
QSI	300,000	$603	12/31/2023
General American Investors Co. Inc.	294,350	$592	12/31/2023
QSI	294,350	$592	12/31/2023
Guggenheim Capital LLC	289,473	$582	12/31/2023
QSI	289,473	$582	12/31/2023
Nuveen Asset Management LLC	289,535	$582	12/31/2023
QSI	289,535	$582	12/31/2023
Citadel Advisors LLC		$538	12/31/2023
Call	163,300	$328	12/31/2023
QSI	125,130	$252	12/31/2023
Put	21,000	$42	12/31/2023
Charles Schwab Investment Management Inc.	260,595	$524	12/31/2023
QSI	260,595	$524	12/31/2023
Morgan Stanley	243,275	$489	12/31/2023
QSI	243,275	$489	12/31/2023
Bank of America Corp DE	189,822	$382	12/31/2023
QSI	189,822	$382	12/31/2023
Invesco Ltd.	187,934	$378	12/31/2023
QSI	187,934	$378	12/31/2023
Barclays PLC	169,608	$342	12/31/2023
QSI	169,608	$342	12/31/2023
Neumann Advisory Hong Kong Ltd	166,198	$327	03/31/2024
QSI	166,198	$327	03/31/2024
Rhumbline Advisers	140,771	$283	12/31/2023
QSI	140,771	$283	12/31/2023
Green Alpha Advisors LLC	134,616	$265	03/31/2024
QSI	134,616	$265	03/31/2024
Pathstone Holdings LLC	115,742	$233	12/31/2023
QSI	115,742	$233	12/31/2023
UBS Group AG	111,189	$223	12/31/2023
QSI	111,189	$223	12/31/2023
Goldman Sachs Group Inc.	106,078	$213	12/31/2023
QSI	106,078	$213	12/31/2023
Tower Research Capital LLC TRC	87,441	$176	12/31/2023
QSI	87,441	$176	12/31/2023
Susquehanna International Group LLP		$168	12/31/2023
QSI	106,445	$214	12/31/2023
Put	49,900	$100	12/31/2023
Call	27,000	$54	12/31/2023
TIG Advisors LLC	82,577	$166	12/31/2023
QSI	82,577	$166	12/31/2023
Two Sigma Investments LP	75,891	$153	12/31/2023
QSI	75,891	$153	12/31/2023
JPMorgan Chase & Co.	69,049	$139	12/31/2023
QSI	69,049	$139	12/31/2023
Alliancebernstein L.P.	55,200	$111	12/31/2023
QSI	55,200	$111	12/31/2023
Price T Rowe Associates Inc. MD	53,782	$109	12/31/2023
QSI	53,782	$109	12/31/2023
MetLife Investment Management LLC	53,683	$108	12/31/2023
QSI	53,683	$108	12/31/2023
American International Group Inc.	50,573	$102	12/31/2023
QSI	50,573	$102	12/31/2023
Cookson Peirce & Co. Inc.	50,000	$101	12/31/2023
QSI	50,000	$101	12/31/2023
Wells Fargo & Company MN	48,458	$97	12/31/2023
QSI	48,458	$97	12/31/2023
HRT Financial LP	45,313	$91	12/31/2023
QSI	45,313	$91	12/31/2023
Voya Investment Management LLC	44,607	$90	12/31/2023
QSI	44,607	$90	12/31/2023
Principal Financial Group Inc.	43,301	$87	12/31/2023
QSI	43,301	$87	12/31/2023
The Manufacturers Life Insurance Company	42,874	$86	12/31/2023
QSI	42,874	$86	12/31/2023
Deutsche Bank AG	42,865	$86	12/31/2023
QSI	42,865	$86	12/31/2023
Red Wave Investments LLC	37,000	$74	12/31/2023
QSI	37,000	$74	12/31/2023
Commonwealth Equity Services LLC	33,710	$68	12/31/2023
QSI	33,710	$68	12/31/2023
Cambridge Investment Research Advisors Inc.	33,355	$67	12/31/2023
QSI	33,355	$67	12/31/2023
Royal Bank of Canada	31,844	$64	12/31/2023
QSI	31,844	$64	12/31/2023
Raymond James Financial Services Advisors Inc.	30,500	$61	12/31/2023
QSI	30,500	$61	12/31/2023
Shay Capital LLC	29,338	$59	12/31/2023
QSI	29,338	$59	12/31/2023
State Board of Administration of Florida Retirement System	29,040	$58	12/31/2023
QSI	29,040	$58	12/31/2023
New York State Common Retirement Fund	26,087	$52	12/31/2023
QSI	26,087	$52	12/31/2023
Guidance Point Advisors LLC	25,742	$52	12/31/2023
QSI	25,742	$52	12/31/2023
Two Sigma Advisers LP	23,400	$47	12/31/2023
QSI	23,400	$47	12/31/2023
Strs Ohio	21,300	$42	12/31/2023
QSI	21,300	$42	12/31/2023
Wolverine Trading LLC		$36	12/31/2023
Call	21,500	$43	12/31/2023
Put	13,900	$28	12/31/2023
QSI	10,399	$21	12/31/2023
SG Americas Securities LLC	17,341	$35	12/31/2023
QSI	17,341	$35	12/31/2023
GTS Securities LLC	17,476	$35	12/31/2023
QSI	17,476	$35	12/31/2023
Squarepoint Ops LLC	17,515	$35	12/31/2023
QSI	17,515	$35	12/31/2023
California State Teachers Retirement System	16,747	$34	12/31/2023
QSI	16,747	$34	12/31/2023
ProShare Advisors LLC	16,840	$34	12/31/2023
QSI	16,840	$34	12/31/2023
DLK Investment Management LLC	17,000	$33	03/31/2024
QSI	17,000	$33	03/31/2024
Citigroup Inc.	15,176	$31	12/31/2023
QSI	15,176	$31	12/31/2023
Ameriprise Financial Inc.	14,300	$29	12/31/2023
QSI	14,300	$29	12/31/2023
Flagship Private Wealth LLC	14,158	$28	12/31/2023
QSI	14,158	$28	12/31/2023
Round Rock Advisors LLC	13,935	$28	12/31/2023
QSI	13,935	$28	12/31/2023
Procyon Private Wealth Partners LLC	13,671	$27	03/31/2024
QSI	13,671	$27	03/31/2024
Victory Capital Management Inc.	13,384	$27	12/31/2023
QSI	13,384	$27	12/31/2023
GWM Advisors LLC	13,742	$26	12/31/2023
QSI	13,742	$26	12/31/2023
Jane Street Group LLC	12,214	$25	12/31/2023
QSI	12,214	$25	12/31/2023
Stratos Wealth Advisors LLC	11,810	$23	03/31/2024
QSI	11,810	$23	03/31/2024
Ameritas Investment Partners Inc.	9,906	$20	12/31/2023
QSI	9,906	$20	12/31/2023
TriaGen Wealth Management LLC	10,000	$20	12/31/2023
QSI	10,000	$20	12/31/2023
Legal & General Group Plc	9,294	$19	12/31/2023
QSI	9,294	$19	12/31/2023
Amalgamated Bank	8,507	$17	12/31/2023
QSI	8,507	$17	12/31/2023
Group One Trading L.P.		$12	12/31/2023
Call	7,000	$14	12/31/2023
Put	1,000	$2	12/31/2023
FMR LLC	5,288	$11	12/31/2023
QSI	5,288	$11	12/31/2023
Advisor Group Holdings Inc.	4,827	$10	12/31/2023
QSI	4,827	$10	12/31/2023
Metropolitan Life Insurance Co NY	1,628	$3	12/31/2023
QSI	1,628	$3	12/31/2023
Archer Investment Corp	1,399	$3	12/31/2023
QSI	1,399	$3	12/31/2023
Principal Securities Inc.	891	$2	12/31/2023
QSI	891	$2	12/31/2023
Allworth Financial LP	836	$2	12/31/2023
QSI	836	$2	12/31/2023
Steward Partners Investment Advisory LLC	1,000	$2	12/31/2023
QSI	1,000	$2	12/31/2023
Comerica Bank	513	$1	12/31/2023
QSI	513	$1	12/31/2023
Eagle Bay Advisors LLC	277	$1	12/31/2023
QSI	277	$1	12/31/2023
TD Waterhouse Canada Inc.	300	$1	12/31/2023
QSI	300	$1	12/31/2023
CWM LLC	9	$0	03/31/2024
QSI	9	$0	03/31/2024
Proequities Inc.	0	$0	12/31/2023
QSI	0	$0	12/31/2023
Nisa Investment Advisors LLC	38	$0	12/31/2023
QSI	38	$0	12/31/2023
FSA Wealth Management LLC	100	$0	12/31/2023
QSI	100	$0	12/31/2023