From speech to the International Energy Agency in Paris:

“There are three reasons why I believe that we should consider position limits in the energy markets. First, our statute mandates it. In 1936, the Congress said that the CFTC “shall” impose limits on trading and positions to guard against the undue burdens that may come as a result of excessive speculation. We are directed by statute to act in this regard to protect the American public.
Second, I believe that position limits should be consistently applied across markets for physical commodities of finite supply. Though there are some differences between energy markets and agricultural markets, I am not sure that those distinctions suggest position limits should be on one and not the other.
Third, I believe that a key principle in promoting market integrity is ensuring markets do not become too concentrated. Last year’s financial crisis highlighted the risk to the market brought about by large concentrated actors on the financial stage.
Position limits can enhance liquidity by promoting more market participants rather than allowing a limited number of parties to dominate a market and possibly decrease liquidity.”