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....

While effective spreads during nocturnal hours are worse compared to regular hours, realized spreads (a measure of intermediation costs) are about the same or better

We also find significant price discovery between 8 PM and 4 AM, particularly for exchange-traded products

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