Quote from Maverick74:
That's two data points. Not exactly statistically significant.
I am too lazy to do it, but that rule has been valid for the last 6-8 or so months. Plenty of data points...
Actually, it has been valid since Nitro actually made a profit...

Edit: One quick example from March 9th, just before the market took a nosedive:
Quote from nitro:
Premarket, so must be taken with a grain of salt, but still highly unusual. FV is above where SPX projects open when futures taken into account!
FWIW: SPX 1321.82. FV 1335.12.
By the inverse rule, he should have shorted it, making plenty of money...
As I said, plenty of data points....