INTERACTIVE BROKERS GRO-CL A (IBKR) Stock Institutional Trading Activity


INTERACTIVE BROKERS GRO-CL A (IBKR) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Renaissance Technologies LLC, Cantillon Capital Management, Egerton Capital UK, Bares Capital Management, and Sequoia Financial Advisors. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q2 2021Thunderbird PartnersSell-262,489889,268$58,452
Q2 2021Renaissance Technologies LLCBuy449,4581,085,658$71,360
Q2 2021Ancient Art (Teton Capital)Sell-52,3801,735,593$114,081
Q2 2021Cantillon Capital ManagementSell-38,2122,359,066$155,062
Q2 2021Bares Capital ManagementSell-342,1565,097,799$335,078
Q1 2021Oakcliff Capital PartnersSell-105,500261,847$19,125
Q1 2021Renaissance Technologies LLCBuy88,800636,200$46,468
Q1 2021Thunderbird PartnersSell-380,5771,151,757$84,124
Q1 2021Ancient Art (Teton Capital)Sell-101,9421,787,973$130,594
Q1 2021Cantillon Capital ManagementSell-81,1432,397,278$175,097
Q1 2021ARK InvestSell-1,1113,002$219
Q1 2021Bares Capital ManagementSell-56,6005,439,955$397,334
Q4 2020Oakcliff Capital PartnersSell-20,939367,347$22,379
Q4 2020Renaissance Technologies LLCBuy118,400547,400$33,348
Q4 2020Thunderbird PartnersBuy6001,532,334$93,350
Q4 2020Cantillon Capital ManagementSell-10,0262,478,421$150,985
Q4 2020ARK InvestSell-162,7444,113$251
Q4 2020Bares Capital ManagementSell-16,0655,496,555$334,850
Q3 2020Renaissance Technologies LLCBuy191,300429,000$20,734
Q3 2020Thunderbird PartnersBuy1,531,7341,531,734$74,029
Q3 2020Ancient Art (Teton Capital)Sell-1,6581,889,915$91,340
Q3 2020Cantillon Capital ManagementSell-25,6362,488,447$120,266
Q3 2020ARK InvestBuy65,391166,857$8,064
Q3 2020Bares Capital ManagementSell-198,6835,512,620$266,425
Q2 2020Renaissance Technologies LLCSell-180,200237,700$9,929
Q2 2020Cantillon Capital ManagementBuy18,7932,514,083$105,013
Q2 2020ARK InvestBuy71,145101,466$4,238
Q2 2020Ariel Appreciation FundBuy275,652275,652$11,514
Q2 2020Bares Capital ManagementSell-368,8095,711,303$238,561
Q1 2020Oakcliff Capital PartnersBuy4,331388,286$16,762

Frequently asked questions about IBKR activity

  • Which institutional owners are buying IBKR?

    Institutional owners buying IBKR include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in IBKR activity?

    "Buy" means an investor increased their reported position in IBKR compared to the prior reporting period. This reflects growing exposure to INTERACTIVE BROKERS GRO-CL A (IBKR) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in IBKR increasing?

    Institutional interest in IBKR can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.