<prompt> Human: I deposited a check into the ATM and when I looked online it was available right away and it said I could spend it. But when I transferred half of it into my savings, my current balance went negative and my available balance was still positive. I got scared and put it back and my current balance was positive again. Sorry if this is a dumb question but Im really confused.  <response>: Was it available or was it available but pending? If it was pending and the transfer was instant you may have transferred money you didnt have. The larger banks Ive had checking accounts with have always taken a day or two to deposit the check and it always went to pending and not cleared right away but they would also take a few days for transfers to clear as well. They also always approve the first one first and go in order so if you do that they wouldnt overdraft. You may have to see how your bank does it and ask them 