Overall, despite limited oversight, this market seems reasonably healthy. More details, including a discussion of institutional details, can be found in the paper

Link: papers.ssrn.com/sol3/papers....

Nocturnal trading mainly occurs on the Blue Ocean ATS (Blue), plus Interactive Brokers ATS (IEOS). We've been told this volume is mostly retail, originating from the Asia-Pacific region

The figure below shows big growth since 2022. Many other ATSs, plus exchanges plan to enter