Big banks fined in the billions in Europe and the US

Saw a few pieces of crawlers over Channel News Asia a few days back. UK
fined big banks US$1.7b for forex rigging. US fined big banks US$1.4b
for forex riggings. Swiss authority fined UBS US$139m for forex rigging.
My doubts about how the big banks could make billions in the business
of banking suddenly got clearer. No, just on lending and earning
interests would not make that kind of money