Freddy...banks and other institutions, with the need or desire, make markets and/or trade in financial instruments which include deposits, FX spot, FX forwards, derivatives of both, etc. Brokers such as R P Martin (owned by Trio) act as middle men publishing the prices at which these principals are willing to deal and bring them together for a commission. So, although you were correct in saying that they do not take on risk as principals, it was not correct to say that they 'make' the products..semantics perhaps but important nevertheless.
Regards
The Vogon