The SEC announcement on Friday came after it found that the platform was inviting people to use its services through its website and Facebook page while also setting up exhibition booths.
The SEC confirmed that CoinEX was not a licensed digital asset operator under the Royal Decree on Digital Asset Businesses (BE 2561).
The watchdog asked people to be cautious when they are persuaded to trade, exchange, deposit, transfer, withdraw, or do transactions related to digital assets because the platform was not regulated by the SEC and hence users will not be protected by the SEC.
The watchdog reiterated its previous warning on the website in the Investor Alert section on May 17.
It said that digital asset operators who advertise, publicise, or persuade must be authorised or they would be punished according to the law.
The SEC urged investors to check the list of licensed digital asset business operators on the website www.sec.or.th or the application SEC Check First.
Investors could also ask or report suspicious business operators on the SEC hotline 1207 for further investigation.