Certain investment banks can pull you in a lot of passive income, but beware, everything comes at a price.
You can see the results of the Zahad Investment Bank here:
These 4 banks are all “High-Risk” investment banks, meaning you can lose money. But on average they are pulling in about +125mil a month per bank.
The issue arises in the fact that in order to use these banks, you need a rank one house. The house spaces are very limited in these cities (with the exception of Valencia City). So in order to aquire a rank one house, you need to outbuy (pearl store furniture) the current rank 1 house. You may say “Oh that’s not so bad, I want my free 125mil a month so I’ll throw a bit of money in and be done with it.” Well every single current rank 1 house is literally completely covered with pearl store items. There is not a single space on any of the floors to place anything new. Here’s where the most frusterating part comes in. Pearl Abyss releases new furniture quite often. These pieces of furniture often have better geometry than the previous furniture. So that 300 dollars you spent to get a rank one house… well that is all in the old furniture and now anyone who buys 301 dollars worth of the new furniture will be able to take your house and you can never win it back and you are out 300 dollars.
So basically if you want to use these banks, be prepared to continually open your wallet.
Below is a rough estimate of the cost you are looking to have to pay for the most highly contested housing in Black Desert: