Summary
Updated Aug 30, 2026
William Peterffy files SEC Form 4 reports at Interactive Brokers Group, Inc. (IBKR). 2 SEC Form 4 filings on record, most recently on 26 January 2026.
Recent Transactions
2Every recent SEC Form 4 transaction William Peterffy has reported, most recent first.
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades in the last 12 months at the companies William Peterffy files at. Multiple unrelated insiders buying the same stock within a short window, cluster buying, has historically been one of the strongest Form 4 signals.
- Paul Jonathan Brody - $59.13M of IBKR open-market activity in the last 12 months
- Earl H. Nemser - $11.76M of IBKR open-market activity in the last 12 months
- Lawrence E. Harris - $5.77M of IBKR open-market activity in the last 12 months
- Jill Bright - $26K of IBKR open-market activity in the last 12 months
- Lori A. Conkling - $16K of IBKR open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
Frequently Asked Questions
Who is William Peterffy?
William Peterffy is a corporate insider of Interactive Brokers Group, Inc. (IBKR). InsiderAlpha holds 2 primary Form 4 filings for them, the earliest from 2026, updated as new SEC EDGAR filings are processed.
When did William Peterffy last file a Form 4?
The most recent primary Form 4 on record is dated 26 January 2026, one of 2 filings going back to 2026.
Where can I see all of William Peterffy's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
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