On Wed. March 16, 2011, we used the new Option Wizard® Simplified Options Strategy (SOS) Backtester to determine some expiration probabilities for SPY.
Previous close: SPY 128.56 Tues Mar 15, 2011
THE PROBABILITIES FOR SPY CLOSE 2 DAYS LATER:
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136 | 0.79% |
134 | 1.97% |
132 | 6.71% |
130 | 22.11% |
128 | 54.64% |
126 | 11.69% |
124 | 4.11% |
122 | 1.66% |
120 | 0.95% |
118 | 0.63% |
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So where did it close, Friday, March 18, 2011 -- options expiration?
Very near our highest probability 128, which Option Wizard® put at 54% probability. Doesn't mean SPY couldn't have closed at 136 or 118, it could have. Theoretically. But where should we put our confidence? Where should we place our positions.
Btw, I mentioned this exercise to a colleague as I was doing it. He is a financial engineer, Chicago firm, fan of fat tails, black swans, and N. Taleb. He scoffed. I understood, he had/has a point.
Still, even in a week (a prior month) of
- Big moves, bull & bear
- Aftermath: Earthquake, 5th worst
- Aftermath: Tsunami
- Ongoing and raging and worsening nuclear catastrophe
It is perhaps nothing short of amazing that plain, vanilla probabilities --prevailed.