Private company
Who owns BOX Options Exchange, LLC
One company in the researched set discloses a stake in BOX Options Exchange, LLC, none of it sized by anyone who discloses it. BOX Options Exchange, LLC is private, so no 13F reports it: a 13F covers exchange listed positions only. These figures exist because each holder disclosed the stake in its own filings.
BOX Options Exchange, LLC - Profile
- Type
- joint venture
- Based in
- United States
- Founded
- 2002
BOX is a United States equity options market, run as a facility of BOX Exchange LLC, a national securities exchange registered with the Securities and Exchange Commission under Section 6 of the Securities Exchange Act of 1934. It lists and trades options on roughly 1,500 underlying securities with competing market makers, and it combines an electronic order book with a physical trading floor. Originally known as the Boston Options Exchange, it was organised in 2002 and began trading in February 2004, and its distinguishing feature at launch was the Price Improvement Period, an exposure auction in which a broker guarantees a price one penny better than the national best bid or offer and other participants are given a brief window to improve on it, bringing price improvement auctions to retail order flow. It is headquartered in Boston, Massachusetts.
Source
BOX Options Exchange, LLC files nothing with the SEC, so none of this comes from a filer record. The description was written for this site in August 2026 from Boston Options Exchange (Wikipedia), BOX Exchange LLC official site and Boston Options Exchange (BOX) education page, Interactive Brokers. The ownership figures below come from the holders' filings instead, and are sourced row by row.
The disclosed stakes
One row per position. Where a holder reports the same company in two share classes, both rows are shown rather than summed, because the class is part of a position's identity.
Where each figure comes from
A private stake has no ownership form behind it, so the source is always the holder's own filing or disclosure. Anything modelled says so, with the arithmetic.
- Interactive Brokers Group, Inc.. IBKR's 10-Q (period 30 Jun 2026) names BOX Options Exchange, LLC as one of its 'strategic investments in certain electronic trading exchanges.' The Investments note discloses only combined totals for the whole book: equity method investments $154m, investments in equity securities at adjusted cost $39m, at fair value $39m, and exchange memberships and equity securities of certain exchanges $2m (total $234m at 30 Jun 2026, vs $288m at 31 Dec 2025), none split by investee. No share count, ownership percentage or per-investee carrying value is disclosed anywhere in the 10-Q or the FY2025 10-K, so nothing is modelled here. source
What this page is not
It is not a complete register. It lists the holders who happen to be inside the researched set and disclosed the stake themselves. A private company can have many other shareholders, and nothing here rules them out: venture investors, founders and employees usually appear in no public filing at all. Percentages are of BOX Options Exchange, LLC where a holder stated one, and are missing where no holder did.