I have learned through experience that is is best to always signal a change in anything after you have applied.
You get a bank letter of your updated funds, if it is quite more significant than your first one. Make a copy, have it notarized by a notary public, write your file number on it, with a cover letter stating that you wish this to be added to your file.
Also, always pay all the immigrations fees at once, because it saves lots of time, both for you and immigration as, they don't have to write to you and you sending it back. It does save months of waiting as there is no back and forth writing and sending. If you are not accepted they will send all your money back except the filing fee.
It is written in the forms now, if you wish to send the entire payment you can. Trust me it does save time and money.
Always send in any change in your status..you can never send too many documents to immigration about your status.