Stocks in September have been negative for four years in a row but momentum from the rate cut could bring change.

For Tesla stock, who needs robotaxis when you have interest rates?Tesla stock was down to start trading on Friday after an epic gain on Thursday.Shares of the electric vehicle maker were off 1.8% at $239.

The federal funds rate is a benchmark that influences other interest rates throughout the economy. The Federal Reserve doesn't control the federal funds rate directly. Instead, it uses various monetary policy tools to steer the benchmark toward a target range, which is currently 4.75% to 5%.