New venues, custody and prime brokerage services are being built for institutions.
Firms engaging in important liquidity-providing roles, including in U.S. Treasuries, will need to register.
OCC said fourth quarter trading revenue was $7.5bn.
Last year voluntary carbon markets traded more than $1bn in notional value for the first time.
Integration with Broadway Technology allows trades to be executed in a single order.
The regulated digital asset securities market is due to launch in the first half of 2022.
The market maker will join TP ICAP's Digital Assets Spot platform, set to launch this year.
INX listed in the the first SEC-registered initial public offering of a digital security.
The crypto futures market is three times bigger than spot.