We employ data over 2005-2009 which uniquely identify categories of traders to test whether speculators like hedge funds and swap dealers cause price changes or volatility. We find little evidence that speculators destabilize financial markets. To the contrary, speculative trading activity...

The coincident rise in crude oil prices and increased number of financial participants in the crude oil futures market from 2000-2008 has led to allegations that “speculators” drive crude oil prices. As crude oil futures peaked at $147/bbl in July 2008, the role of speculators came under...