Unlike certificates of deposit, which maintain a constant interest rate for the term of the certificate, high-yield savings account rates are variable rates. That means they’re determined by market factors, which can change frequently.
While there are some high-yield savings accounts that may offer a high rate for a specific term, most are consistently at the upper end of the interest rate range. For example, the banks that are currently paying the highest rates on savings accounts now were the same ones paying high rates one or two years ago.