Yeah, but how do you KNOW that these are "spurious," hmmm?
Have I shared my lottery story? The sales/Account guys came to me a while ago and asked for technique for predicting winning numbers in the mega-drawing games, reasoning that some numbers must be hot. It's true, some numbers will for a time appear more frequently on consecutive days than random selection would predict, but the trouble is that these deviations are small and by the time that you've noted an anomally it has probably passed. So, instead, I offered this: correlate sales of stock by the officers of public companies with high points in the value of said stock. Sales by officers is a matter of public record, as is daily close price of shares. By looking at a handful of companies with which I have some familiarity I was able to demonstrate that some insiders got it right more often than did others and sold at temporary highs. Leave aside conspiracy theories of stock price manipulation for a second and think about the implications: some officers of public companies are in effect canaries in the coal mine signalling the right time at which to sell. Wow. Trouble is, of course, that these sale data are not reported in real time, meaning that if you work for the FTC you might be interested, but as an investor looking for an angle the news comes way, way too late to be acted upon.