Stock index futures trading collection

Stock index futures offer fertile fields for spread traders. Consider only the S&P 500 and the Nasdaq 100. Apart from the obvious difference in the numbers of stocks they contain, the two indices vary considerably in terms of the size and type of their component companies. As a result, it should not be surprising they exhibit markedly different volatility in response to economic stimuli.

This would seem to lay the seeds of productive spread trading, but stock index futures have gone largely untilled in this regard.