Compounder

Interactive Brokers Gro-Cl A

Held by 6 superinvestors (IBKR).

Educational data only — not investment advice. 13F positions are self-reported and can lag up to 45 days.

This quarter1 opened1 added3 trimmed
TickerIBKR
Holder count6
Total value held$1.39B
Largest holderWilliam von Mueffling
External
Ownership overview

Interactive Brokers Gro-Cl A (IBKR) is held by 6 of the superinvestors tracked on Compounder, with a combined $1.39B in reported 13F value. The largest position belongs to William von Mueffling, where it makes up 5.0% of the portfolio.

Other notable holders by value include John Armitage (4.7% of its book), Andreas Halvorsen (0.3% of its book) and Bryan Lawrence (30.5% of its book).

Over the latest quarter, 1 of the tracked filers opened a new position in IBKR, 1 added to existing ones, 3 trimmed, and 0 sold out entirely.

Holder counts and values reflect the most recent SEC Form 13F filings, through the quarter ended 2026-03-31. Source: SEC EDGAR. A 13F shows only long US-listed positions and can lag the real portfolio by up to 45 days, so this is disclosed long ownership, not a complete picture.

Holders over time

Superinvestors holding this security over the last 8 quarters: 5 → 6.

Early quarters may understate holder counts due to data backfill — read the slope with care.

Superinvestors Holding This Security

Sources· SEC EDGAR 13F as of 2026-05-15

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