Investigate / reported ownership
IBKR
Interactive Brokers Gro-cl A
7 tracked reported owners · snapshot updated 2026-10-04. Delayed disclosures, not live holdings or an investment recommendation.
Who reports owning IBKR?
Select a manager to inspect their portfolio. Reports may cover different quarters; portfolio weights describe disclosed long 13F holdings, not total economic exposure.
| #↑ | Manager | % Port. | History | Value | Shares |
|---|---|---|---|---|---|
| 1 | Viking Global Investors | 1.2% | 2q | $420M | 4,830,748 |
| 2 | John Armitage | 3.5% | 10q | $359M | 4,129,416 |
| 3 | Joel Greenblatt | 0.1% | 36q | $94M | 1,081,743 |
| 4 | Bryan Lawrence | 33.4% | 38q | $90M | 1,030,740 |
| 5 | Stephen Mandel | 0.3% | — 1q | $50M | 577,666 |
Go beyond ownership.
Interactive Brokers is an automated global broker that custodies accounts and routes, executes and processes trades across many asset types on electronic exchanges worldwide for funds, advisors, trading groups and individual investors.
Question to investigate: Can its automated, low-cost platform keep serving a diverse customer base while revenues swing with trading activity and interest rates?
Company research reviewed 2026-10-03; a dated source-linked starting point, not the investors’ stated reasons.
Understand the business and investment case →Filing dates and original SEC sources
- Viking Global Investors · 2026Q2 · filed 2026-08-14 ↗
- John Armitage · 2026Q2 · filed 2026-07-21 ↗
- Joel Greenblatt · 2026Q2 · filed 2026-09-02 ↗
- Bryan Lawrence · 2026Q2 · filed 2026-08-13 ↗
- Stephen Mandel · 2026Q2 · filed 2026-08-14 ↗
- Robert Vinall · 2026Q2 · filed 2026-08-14 ↗
- William Von Mueffling · 2026Q2 · filed 2026-07-29 ↗
Reported position changes
Net disclosed share changes—not individual trades or execution dates. NEW has no prior-position percentage comparison; EXIT weight refers to the previous report.
| Manager | Move | % Port. | Δ Shares | Value | Filed |
|---|---|---|---|---|---|
| Robert Vinall | TRIM | 12.8% | -26% | $49M | Aug 14, 2026 |
| Stephen Mandel | NEW | 0.3% | New position | $50M | Aug 14, 2026 |
| William Von Mueffling | TRIM | 6.8% | -95% | $45M | Jul 29, 2026 |
| John Armitage | TRIM | 3.5% | -34% | $359M | Jul 21, 2026 |
Keep your next step small.
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Long US 13F disclosures omit shorts and can be amended. CUSIP 45841N107. No current price, valuation or manager motive is inferred.