TMX Group agreed on 30 July to make a strategic investment of about $800m in MEMX and combine it with BOX, giving TMX about 59% of a US exchange group valued at about $2.3bn.
Why TMX Group Limited is buying MEMX
The combined company will run three US listed options exchanges and an equities exchange, plus a market technology business. MEMX chief executive Jonathan Kellner, who will lead the group, said adding BOX's electronic and open-outcry trading lets it compete across all US options exchange models.
“TMX is a long-standing investor in the US options market, and today we are pleased to announce a significant increase in our stake with the investment in MEMX.”
Deal terms and financing
The new entity is funded by TMX's roughly $800m equity investment, a rollover of TMX's BOX interest, rollovers by MEMX and BOX investors including Citadel Securities, Jane Street, Morgan Stanley, Schwab and Virtu, and an investment from Markets Infrastructure Partners. TMX and minority holders get call and put rights respectively from three years after closing.
Regulatory approvals and timing
The transaction is expected to close in the second half of 2027, subject to regulatory approval.
Market context
MEMX and BOX generated combined 2025 revenue of about $280m and adjusted EBITDA of about $134m. TMX chief executive John McKenzie said the deal significantly increases its stake in the US options market.
