Banks: loans and deposits
In the game, inside of the bigger cities, you can find a bank institution. They allow you to take loans with a certain (variable) interest rate and an amount of money taken for a fixed term. When after that amount of time you didn't return the loan the money will be taken from your account - the money can be returned at any bank. If you want to take a loan in a given bank you must have a high reputation in that city.
Banks can also offer deposits. If you want to take some rest from storyline quests and, at that moment, you don't need a lot of money you can deposit them. After some time (usually after a month and a half) you receive even up to 10% profit from the deposited money. For this action you also need a high reputation but the required amount is lower than the one required for loans. After establishing the conditions a deposit will appear as a quest. After a certain amount of time you can withdraw your money from any bank. However, you can't do it before a determined amount of time passes.
Auctions appear in the storyline only after you start a quest called Daniel Drew; in free mode they are available from the beginning. You can see them in the Events tab. In the auctions you can find properties that generate a fixed amount of money or goods. A starting price is always showed to you and it depends on building's value. If you want to take part in an auction you must head to a specified city before the time runs out and enter a city hall - there you can see an auction (requires a positive reputation, about 40 points).
An auction happens in real time. On the screen you can see your rivals and below them the current price is displayed. You can raise the bid or withdraw from an auction at any time. An auction ends when no one can give more than a price that was given by another person (those that withdraw from an auction are marked by gray color). Sometimes a final price can be five times higher than the starting price which means that you must participate in an auction with a lot of money.