The US stock market has been volatile in recent weeks, dominated by uncertainty about the Federal Reserve’s next move on interest rates and China’s ability to stabilise its stock markets and get its economy moving. Many investors have begun moving to the sidelines ahead of the Fed meeting this Wednesday and Thursday. In any case, observers believe the possibility of an interest-rate increase has already been priced into stocks. As a result, the Dow gained 0.5% on Thursday and rose another 102 points on Friday to close at 16,433.09, up 2.7% from the week before.