Institutional HoldersBeta

Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.

Arqit Quantum Inc.

CIK 0001859690ARQQ· quarter ending 2026-06-30

Shares outstanding

15,291,767

as of 2025-09-30 · 20-F cover page, filed 2025-12-09

Held by 13F filers

12,307,347

80.5% of shares outstanding

Holders

+8 vs 2026-03-31 · 21 new, 13 exited

Value

$360.6M

shares +206.2% vs prior quarter

Share classes (cover page of the 20-F filed 2025-12-09, as of 2025-09-30)

Class	Listed	Shares outstanding	Held by 13F filers	% of class	Holders	CUSIP
Common stock	ARQQ · NASDAQ	15,291,767	12,307,347	80.5%	64	G0567U127

Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.

Securities (CUSIPs held in 13F this quarter)

tick to combine

Count	CUSIP	Class (as filers write it)	Holders	Shares held	Class shares	% of class	Value	Options	Mapped via
	G0567U127	COM	64	12,307,347	15,291,767	80.5%	$360.6M	5 call / 6 put	13DG	holders →
	G0567U119	WTSnot common	11	6,230,595	—	—	$445K	1 call / 0 put	prefix	holders →

Totals combine the ticked CUSIPs and update as you tick: common-stock classes by default; preferreds, notes, warrants and depositary shares are listed but not counted. "holders →" shows a single CUSIP on its own. Bonds are held as a principal amount, not shares. Options positions are never counted as holdings. 1 further CUSIPs map to this company (mostly bonds) but no 13F filer held them this quarter.

Top holders (64 of 64 · G0567U127)

change vs 2026-03-31

#	Filer	Shares	% of class	Value	Change
1	Defiance ETFs, LLC	5,099,023	33.34%	$147.1M	+3,646,712 (+251.1%)
2	Penserra Capital Management LLC	5,081,219	33.23%	$151.0M	+3,628,908 (+249.9%)
3	UBS Group AG	522,874	3.42%	$15.5M	+437,439 (+512.0%)
4	Legal & General Group Plc	275,939	1.80%	$8.1M	+223,307 (+424.3%)
5	NATIONAL BANK OF CANADA /FI/	212,000	1.39%	$6.3M	+210,907 (+19296.2%)
6	MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.	188,182	1.23%	$5.6M	-136,127 (-42.0%)
7	Kessler Investment Group, LLC	153,105	1.00%	$4.6M	-4,464 (-2.8%)
8	Bank of New York Mellon Corp	99,146	0.65%	$2.9M	+87,234 (+732.3%)
9	RAYMOND JAMES FINANCIAL INC	95,250	0.62%	$2.8M	+31,413 (+49.2%)
10	MILLENNIUM MANAGEMENT LLC	78,717	0.51%	$2.3M	+24,691 (+45.7%)
11	BANK OF AMERICA CORP /DE/	54,192	0.35%	$1.6M	+35,000 (+182.4%)
12	VAN ECK ASSOCIATES CORP	49,487	0.32%	$1.5M	+29,334 (+145.6%)
13	Cetera Investment Advisers	38,198	0.25%	$1.1M	NEW
14	BANQUE PICTET & CIE SA	36,000	0.24%	$1.1M	—
15	KKM Financial LLC	31,394	0.21%	$538K	NEW
16	Man Group plc	26,210	0.17%	$779K	NEW
17	SBI Securities Co., Ltd.	26,135	0.17%	$777K	-974 (-3.6%)
18	Advisory Services Network, LLC	21,737	0.14%	$646K	-10 (-0.0%)
19	Zurcher Kantonalbank (Zurich Cantonalbank)	21,296	0.14%	$633K	+11,318 (+113.4%)
20	WELLS FARGO & COMPANY/MN	21,291	0.14%	$633K	+6,198 (+41.1%)
21	LPL Financial LLC	17,109	0.11%	$508K	NEW
22	MORGAN STANLEY	16,276	0.11%	$484K	+6,897 (+73.5%)
23	Tidal Investments LLC	16,020	0.10%	$476K	NEW
24	CITIGROUP INC	14,572	0.10%	$433K	+4,725 (+48.0%)
25	GROUP ONE TRADING LLC	12,682	0.08%	$377K	-774 (-5.8%)
26	SIMPLEX TRADING, LLC	11,472	0.08%	$341K	NEW
27	ROYAL BANK OF CANADA	9,519	0.06%	$283K	+2,507 (+35.8%)
28	GEODE CAPITAL MANAGEMENT, LLC	9,294	0.06%	$276K	NEW
29	Y.D. More Investments Ltd	8,881	0.06%	$886	NEW
30	HSBC HOLDINGS PLC	8,453	0.06%	$249K	NEW
31	Heck Capital Advisors, LLC	7,882	0.05%	$234K	NEW
32	GOLDMAN SACHS GROUP INC	7,293	0.05%	$217K	NEW
33	McGuire Investment Group, LLC	6,928	0.05%	$206K	NEW
34	BlackRock, Inc.	6,587	0.04%	$196K	+4,355 (+195.1%)
35	JONES FINANCIAL COMPANIES LLLP	4,071	0.03%	$99K	+675 (+19.9%)
36	Mirae Asset Global Investments Co., Ltd.	3,444	0.02%	$102K	-2,402 (-41.1%)
37	OSAIC HOLDINGS, INC.	3,215	0.02%	$96K	+1,368 (+74.1%)
38	Center for Financial Planning, Inc.	2,818	0.02%	$84K	NEW
39	Leonteq Securities AG	1,500	0.01%	$45K	-225 (-13.0%)
40	Tower Research Capital LLC (TRC)	1,254	0.01%	$37K	NEW
41	Rockefeller Capital Management L.P.	1,000	0.01%	$30K	NEW
42	EFG International AG	1,000	0.01%	$30K	—
43	HARBOUR INVESTMENTS, INC.	900	0.01%	$27K	+100 (+12.5%)
44	Steward Partners Investment Advisory, LLC	600	0.00%	$18K	—
45	SIGNATUREFD, LLC	600	0.00%	$18K	—
46	Ameritas Advisory Services, LLC	564	0.00%	$17K	NEW
47	BNP PARIBAS FINANCIAL MARKETS	563	0.00%	$17K	NEW
48	WOLVERINE ASSET MANAGEMENT LLC	489	0.00%	$15K	—
49	IFP Advisors, Inc	185	0.00%	$5K	-940 (-83.6%)
50	Farther Finance Advisors, LLC	172	0.00%	$5K	NEW
51	Heritage Wealth Advisors	130	0.00%	$4K	—
52	Parallel Advisors, LLC	122	0.00%	$4K	-140 (-53.4%)
53	West Financial Advisors, LLC	100	0.00%	$3K	—
54	Core Capital Management & Research, inc.	44	0.00%	$930	NEW
55	Quarry LP	40	0.00%	$1K	NEW
56	DEUTSCHE BANK AG\	40	0.00%	$1K	NEW
57	US BANCORP \DE\	35	0.00%	$1K	-100 (-74.1%)
58	Investors Portfolio Services LLC	28	0.00%	$832	—
59	Cornerstone Financial Management LLC	25	0.00%	$743	-14 (-35.9%)
60	CoreCap Advisors, LLC	16	0.00%	$476	—
61	Parkside Financial Bank & Trust	16	0.00%	$476	—
62	MCF Advisors LLC	10	0.00%	$298	—
63	TD Waterhouse Canada Inc.	2	0.00%	$57	—
64	HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND	1	0.00%	$30	—

Exited since 2026-03-31 (13 filers; largest 13 shown)

RENAISSANCE TECHNOLOGIES LLC	−41,400
TUDOR INVESTMENT CORP ET AL	−38,069
JANE STREET GROUP, LLC	−33,199
True Vision MN LLC	−14,848
Headlands Technologies LLC	−12,321
Stonehage Fleming Financial Services Holdings Ltd	−11,528
Allworth Financial LP	−1,000
Federation des caisses Desjardins du Quebec	−696
Quantbot Technologies LP	−444
Sunbelt Securities, Inc.	−250
MAI Capital Management	−200
Basecamp Wealth Advisors LLC	−38
Vermillion Wealth Management, Inc.	−1

Large holders from 13D/13G (latest per reporting person, last 2 years)

Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.

Reporting person	Form	Filed	Event	Shares	% of class
Notion Capital III LP	SCHEDULE 13G/A	2026-09-10	2026-06-26	1,812,206	10%
Millennium Management LLC	SCHEDULE 13G	2026-06-23	2026-06-16	58,621	0.3%
ICS Opportunities, Ltd.	SCHEDULE 13G	2026-06-23	2026-06-16	7,800	0%
Israel A. Englander	SCHEDULE 13G	2026-06-23	2026-06-16	58,621	0.3%
Millennium Group Management LLC	SCHEDULE 13G	2026-06-23	2026-06-16	58,621	0.3%
Heritage Assets SCSp	SCHEDULE 13D/A	2026-05-26	2026-05-21	9,249,963.8	38.4%
Manfredi Lefebvre d'Ovidio	SCHEDULE 13D/A	2026-05-26	2026-05-21	9,298,313.8	38.6%
M Management S.A.	SCHEDULE 13D/A	2026-05-26	2026-05-21	9,249,963.8	38.4%
Heritage Assets SCSp.	SCHEDULE 13D/A	2025-05-29	2025-05-27	5,776,252	35.8%
Evolution Equity Partners II SARL	SCHEDULE 13D/A	2025-02-10	2024-09-30	397,259	3.1%
The Evolution Technology Fund II SCSP	SCHEDULE 13D/A	2025-02-10	2024-09-30	397,259	3.1%
Bestwick David	SCHEDULE 13D/A	2024-12-18	2024-12-11	414,269	3.3%
D2BW Ltd	SCHEDULE 13D/A	2024-12-18	2024-12-11	251,280	2%
Williams David John	SCHEDULE 13D/A	2024-12-18	2024-12-11	726,723	5.8%

Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.