How to make fast money?

To make more money passively you can change class to trader. They have a money production buff. If you are a raider though you can earn a lot of money by attacking other players (or set up trader farms to attack and gain money from).

Try to station heroes in the bank and unlock skills to give you extra money production. You can also gain money selling spare resources at the commercial hub (helicopter).

I was stuck with raider... no money.... solution was energy sell for money. I made 40 mil in few days.