I created an AEX9 Token with the name WTT.
I send 10 WTTs to account A.
Now account A only has 10WTT, now I use account A to send 100WTT to account B.
The transaction is packaged normally. And it generates a valid TX HASH, available on the chain.
Of course, I can use a negative transfer, send -100wtt, and it will still pack up as normal.
AEX9 lacks judgment on account amount.
While there is no real transfer on the chain, it can be confusing for the blockchain browser, and for the user.