when is last time we opened lower then previous close? Normal up day has been open above previous close but close below open. You could pretty much know in advance what was going to happen.
Example Close at .30 Next open is .36 Stock was going to close below .36 but above .30 So any time SP was above .36 you sold and any time it was below .30 you bought.
You could name a roller coaster at Six Flags "The Sirius"