The New York Mercantile Exchange (Nymex) is doing its level best to give energy traders what it feels they want. In February alone, the energy exchange has announced its intention to open a floor in London, launched several new oil and electricity contracts on its electronic platform ClearPort and has said it will start posting SO2 and NOx trades this year. So why does it not give participants something else lacking from its product roster: a ClearPort-listed contract for average-price