The president has a fiduciary responsibility to the brotherhood. He must serve as the checks and balance on all financial affairs. This is a critically important function that most presidents overlook.
Every brother who has been in the fraternity for a few years has heard of a story where a treasurer skipped town with the entire fraternity bank account. I am sure there are thousands of more stories of treasurers stealing from the fraternity that never get told because they are never caught. The president must make sure his fraternity does not fall victim to theft.
He does this by not allowing the fraternity to purchase anything in cash. Cash is too easy to steal. Then, the bank account must be set up to require two signatures. This ensures that the president and the treasurer both have oversight of every dime of fraternity spending. Finally, the president must ensure that that treasurer gives a thorough financial update to the fraternity at each meeting. There is going to be less frivolous spending if the entire fraternity is going to be made aware of every transaction.
To learn more, check out our most in-depth article on being a fraternity president: How To Be a Great Fraternity President