The investigation is focused on illegal practices that can influence prices -- such as spoofing, or flooding the market with fake orders to trick other traders into buying or selling, said the people, who asked not to be identified because the review is private. Federal prosecutors are working with the Commodity Futures Trading Commission, a financial regulator that oversees derivatives tied to Bitcoin, the people said. Source https://www.bloomberg.com/news/articles/2018-05-24/bitcoin-manipulation-is-said-to-be-focus-of-u-s-criminal-probe. What exchanges can be involved in this story?