Considering the CFTC's policy on position limits, there are actually two
questions that need to be answered.
The first is whether it is true that speculative positions affect
prices. There are good economic reasons to reject this notion. A futures
position is a commitment to deliver a commodity by the short side and a
commitment to take delivery of that commodity by the long side. Those
commitments are distinct from demand or supply of the product. This is
because the long side can immediately sell the commodity received to someone
who wants to consume it. Likewise the short side can buy the commodity
immediately before delivering it per their contract. For the long side,
these constitute transfers of the commodity as opposed to demands for the
purpose of consuming it. Likewise, generally the short side satisfies its
delivery requirement via a transfer rather than through engaging in its actual
production. Examinations of the effect that undertaking positions has on
prices have consistently found no relationship between position changes and
subsequent price changes. This is precisely the result that the above
economic reasoning predicts. That is, unless long positions actually
shift commodity demanded or short positions actually shift commodity supplied,
then trading in futures should have no effect on pricing fundamentals.