A U.S. enforcement case against alleged crypto market manipulation is once again putting the spotlight on wash trading and the blurry line between market makers and market manipulators.

Federal prosecutors in California this week charged 10 individuals tied to firms including Gotbit, Vortex, Antier and Contrarian, accusing them of coordinating trades to inflate token prices and volumes before selling into the artificial demand.

The case stemmed from an undercover FBI operation in which agents created their own token to identify firms offering manipulation services.

Defendants marketed strategies to boost trading activity that in reality amounted to pump-and-dump schemes and wash trading, leaving evidence that is far more common than…