I have to be voice of reason on this speculative piece, all financial institutions use their customers balances to speculate in other markets. It's pretty much how the fiscal economics work, that and inter Bank lending etc.
If they have broken regs etc then maybe a story in it but I'm thinking it's a bit of a nothing burger.
And for the records, I don't want and don't think we should be anywhere near 777.
*I may need to read the article again to see if I've missed anything but hardline investment tactics are not necessarily illegal.