United States Natural Gas Fund ( UNG) -2.4% On Monday, supply issues continued to weigh on natural gas prices and UNG. Aside from the supply issues, a mild weather report didn't bode well for forecasted demand. Throughout April, UNG has been trading sideways. Though I wouldn't recommend playing the fund, it may be interesting to check out which direction it takes in the near future, as it is holding just above all-time lows. All prices as of 2:18 p.m.EST -- Written by Don Dion in Williamstown, Mass.