Cantillon Capital Management LLC

Position in IBKR — Interactive Brokers Group, Inc.

CIK 1279936 New York, NY

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Position in IBKR

as of Mar 31, 2026 · filed May 7, 2026 Compact

Position Value

$754,261,237

-$66,328,189 QoQ

Shares Held

11,245,881

-11.9% QoQ

Ownership

2.52%

of shares outstanding

% of Portfolio

5.04%

of 13F equity value

Holder Rank

—

not a current holder

Holding Since

Mar 2020

25 quarters on record

Voting authority Sole 89.63238184718476.ToString("F0")% Shared 0.ToString("F0")% None 10.36761815281524.ToString("F0")%

Common Shares in IBKR Over Time

Shares Held

Position Value (USD)

Position in Capital Markets

Financial Services · as of Mar 31, 2026

Cantillon Capital Management LLC holds $1,130,515,068 across 3 Capital Markets names. IBKR ranks #1 (66.7% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	IBKR	Interactive Brokers Group, Inc. This page	11,245,881	$754,261,237
2	TW	Tradeweb Markets Inc.	2,367,041	$278,506,043
3	LPLA	LPL Financial Holdings Inc.	324,927	$97,747,788

All Filings in IBKR

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25 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-03-31	$754,261,237	11,245,881	-11.9%	Shares	Defined	2026-05-07
2025-12-31	$820,589,426	12,759,904	+0.8%	Shares	Defined	2026-02-11
2025-09-30	$871,411,628	12,664,026	-1.1%	Shares	Defined	2026-02-17
2025-06-30	$709,449,192	12,803,631	+288.7%	Shares	Defined	2026-02-17
2025-03-31	$136,356,161	3,293,826	-3.0%	Shares	Defined	2026-02-17
2024-12-31	$149,979,137	3,395,690	+0.5%	Shares	Defined	2025-02-05
2024-09-30	$117,677,082	3,377,643	-2.9%	Shares	Defined	2024-11-07
2024-06-30	$106,618,323	3,478,575	-4.8%	Shares	Defined	2024-08-05
2024-03-31	$102,094,672	3,655,704	-2.0%	Shares	Defined	2024-05-08
2023-12-31	$77,280,809	3,728,869	-2.4%	Shares	Defined	2024-02-07
2023-09-30	$82,656,771	3,819,629	-0.4%	Shares	Defined	2023-11-06
2023-06-30	$79,632,313	3,834,468	+6.4%	Shares	Defined	2023-08-09
2023-03-31	$74,394,815	3,604,400	+11.9%	Shares	Defined	2023-05-04
2022-12-31	$58,245,620	3,220,214	+30.3%	Shares	Defined	2023-02-06
2022-09-30	$39,478,357	2,470,872	-0.9%	Shares	Defined	2022-11-03
2022-06-30	$34,283,758	2,492,911	+12.1%	Shares	Defined	2022-08-03
2022-03-31	$36,654,247	2,224,503	+2.9%	Shares	Defined	2022-05-03
2021-12-31	$42,936,278	2,162,492	-7.0%	Shares	Defined	2022-01-27
2021-09-30	$36,247,872	2,325,818	-1.4%	Shares	Defined	2021-10-26
2021-06-30	$38,765,351	2,359,066	-1.6%	Shares	Defined	2021-07-27
2021-03-31	$43,774,295	2,397,278	-3.3%	Shares	Defined	2021-05-03
2020-12-31	$37,746,351	2,478,421	-0.4%	Shares	Defined	2021-02-03
2020-09-30	$30,066,660	2,488,447	-1.0%	Shares	Defined	2020-10-30
2020-06-30	$26,253,311	2,514,083	+0.8%	Shares	Defined	2020-07-31
2020-03-31	$26,930,416	2,495,290	—	Shares	Defined	2020-04-30
No filing history on record for this holder in this stock.