Question 1

Does Cantillon Capital Management own IBKR stock?

Accepted Answer

Yes. As of its Q2 2026 13F, Cantillon Capital Management holds 517,833 shares of IBKR (Interactive Brokers Group in), worth $45.1M.

Question 2

How many shares of IBKR does Cantillon Capital Management own?

Accepted Answer

As of its Q2 2026 13F, Cantillon Capital Management holds 517,833 shares of IBKR (Interactive Brokers Group in).

Question 3

What is Cantillon Capital Management's IBKR position worth?

Accepted Answer

As of its Q2 2026 13F, Cantillon Capital Management's IBKR position is worth $45.1M.

Question 4

Is Cantillon Capital Management buying or selling IBKR?

Accepted Answer

In Q2 2026, Cantillon Capital Management reduced its IBKR position by 10,728,048 shares (-95.4%).

Question 5

When did Cantillon Capital Management first buy IBKR?

Accepted Answer

Cantillon Capital Management already held IBKR in its Q1 2019 13F, the earliest on record, and has listed it in 30 quarterly 13F filings.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q2 Latest	Decreased	517,833	-95.4%	$45.1M	6.8%	$86.96	0
2026-Q1	Decreased	11.2M	-11.9%	$754.3M	5.0%	$66.94	0
2025-Q4	Increased	12.8M	+0.8%	$820.6M	4.4%	$64.12	60
2025-Q3	Decreased	12.7M	-1.1%	$871.4M	4.8%	$68.52	0
2025-Q2	Increased	12.8M	+288.7%	$709.4M	4.1%	$55.11	95
2025-Q1	Decreased	3.3M	-3.0%	$545.4M	3.5%	$41.11	0
2024-Q4	Increased	3.4M	+0.5%	$599.9M	3.6%	$43.80	59
2024-Q3	Decreased	3.4M	-2.9%	$470.7M	2.9%	$34.51	0