The stock markets opened the first day's trading in 2016 on a somewhat volatile note, with the Sensex at the Bombay Stock Exchange swinging between losses and gains, and dropping 64 points, to 26,053 a short while ago. Similarly, the Nifty at the National Stock Exchange had declined 22 points, to 7,925 a short while ago. And at the forex market, the rupee had weakened 5 paise, to 66.20 against the dollar in morning trade.