Business ethics within the EA framework

I’m quite new to Effective Altruism and find the movement compelling. I’m an investor and sometimes come across business opportunities that could be quite profitable but make me uncomfortable being a part of. I’m wondering what many of you would decide to do when faced with a hypo like the below:

Suppose a local government has decided to have a casino in their city and have approached you as a possible development/​operating partner. Assume that:

1) You believe casinos should be illegal due to societal harm caused.

2) You would earn superior returns on your time and financial investment in this casino project vs. any other available venture.

3) If you decline the opportunity, the city will proceed with another partner and the casino will be built regardless.

Would you be a part of this project or decline? Does it matter just how superior the returns are, how high the societal harm is, etc. or does your decision not change?