The PREM or more specifically the S&P Premium, or ES Premium or Nasdaq Premium is one of the few leading indicators that actually works. It will not tell you when to trade. But it will tell you what the ES is going to do sometimes hours before it occurs. The issue is how to read it. While there may be more than one way to read the premium, one of the most effective methods has been publically posted at this link. It really does work. By following these rules you could have known what was going to happen on 5/27/09. You could have known: To short the market precisely at 9:01 cst That the ES would return to 912.75 later in the day That the ES would also short back to at least 907 or less. How did you know this? At 9:01 the SP Prem hit a new low. The rules say this is a classic trend reversal and thats exactly what happened. A short trade their couldn't help but make money. At 9:01 the ES Prem hit a new high. The rules say that either the ES will go back to 912.75 or better or the Prem will go higher. In this both took place. At 10:12 cst the SP Prem hit a new low forecasting a return back to 907 or less. A short trade thereafter made money. A lot of money!