MEMX Merges with BOX in $2.3B Deal, Giving TMX Group Majority Control

MEMX LLC, the upstart exchange operator backed by some of Wall Street’s biggest names, is combining with BOX Options Market in a deal that values the merged entity at roughly $2.3 billion. The twist: Canada’s TMX Group walks away with the keys to the castle, securing approximately 59% ownership of the newly formed MEMX Group.

TMX is putting up around $800 million in cash and rolling its existing stake in BOX to lock in that controlling position. The remaining ownership stays in the hands of MEMX’s original backers, including Jane Street, Morgan Stanley, Citadel Securities, Virtu, and Optiver, who are all rolling equity into the new structure.

MEMX Group will operate three US options exchanges alongside an equities exchange and a technology business.

In 2025, MEMX and BOX generated combined revenue of approximately $280 million, with adjusted EBITDA coming in around $134 million. That’s roughly a 48% EBITDA margin.

MEMX was founded in 2019, originally as a scrappy competitor to the NYSE and Nasdaq duopoly. BOX has operated as a hybrid venue that blends electronic trading with traditional floor-based trading. MEMX has also recently expanded into options trading through its MX2 platform, which is set to launch with a phased rollout beginning in September 2026.

The transaction is expected to close in the second half of 2027, pending regulatory approvals.

MEMX previously supplied the technology backbone for EDX Markets, the digital asset exchange launched with backing from Citadel Securities, Fidelity, and Charles Schwab. While EDX has charted its own course since launch, the relationship demonstrated that MEMX’s technology was built to handle asset classes beyond stocks and options.

TMX Group has its own history with digital assets, having listed crypto ETFs in Canada well before the US approved its first spot Bitcoin ETFs.

The $2.3 billion valuation, at roughly 8x 2025 revenue and 17x EBITDA, prices the deal at a premium that reflects growth expectations beyond today’s revenue streams.