According to CoinMeta, and as announced officially, South Korea's largest cryptocurrency exchange Upbit and the second-largest exchange Bithumb declared on August 24 that they would list The Sandbox ( SAND ) as a transaction caution asset. The reason was that security incidents such as unknown or unfixed hacker attacks were detected in their wallets or distributed ledgers. It is expected that Bithumb will review from September 28 to October 2 whether to lift the transaction caution designation, extend it, or terminate support for trading this asset.