Is it ethical to develop software for financial company?

I'm wondering whether it is ethical to work as software engineer for financial company that develops software for exchanges and banks. When we consider exchange, different things are traded there, i.e. commodities, currency, money and equities. Unfortunately some of commodities are pork bellies (dead hogs), however there are hundreads other goods which are not meat. Moreover, markets are not only for speculators (who risk their money by "gambling") but also hedgers (who want to manage their risk by using financial market, so it's good reason). Also, exchanges make it possible for companies to acquire money for further investments. Furthermore, implementing new legislations makes markets more secure against financial crises, e.g. MIFID II.