Some banks are charging their own rate of exchange.
It happened once to me when someone was sending me money from here to Europe through bank transfer.
Never done it again!

Since then I always transfer by WU to one person, not bank, and always in US$, since this is the currency that WU makes most transactions.

Btw, no one can steal your money "on the way" if you send it by WU. It goes by electronic transfer, so nobody can physically take it.

Why don't you try to do the transfer from local HSBC to the one in your country?
Ask them about fees, too.

If you're looking for a problem, you're probably gonna find one.