The APY that a savings account pays on the day you make your initial deposit is not guaranteed. In fact, the account’s rate can change at any time. Whether the rate goes up or down, and how often it changes, is largely influenced by the Federal Reserve. When it adjusts the federal funds rate, banks and credit unions often follow suit in the same direction. That said, rate changes among savings accounts are not typically a daily or weekly event. Barring recent moves by the Fed, rates often remain at the same level for weeks or months at a time.