Sam Bankman-Fried was in control of FTX, Alameda, and many other entities. He moved customer funds from FTX to Alameda and possibly to himself. It was likely one of the largest misappropriations of customer funds in history. SBF allegedly built a custom-made accounting system to hide the missing assets.
Serum has notified its community that it is now defunct. The community has already forked the project. OpenBook now has over $1 million in daily volume. Serum's volume and liquidity dropped to near zero after the launch of OpenBook. Many users felt like OpenBook was the safer option after Serum was compromised in the FTX hack.