Actually it's skewed. With a larger population that wouldn't show but 5 minus 3 SDs is less than zero but 5 plus 3 SDs is feasible. The ancient rule of thumb remembered from my student days is that you should look for a quantity of at least 30 so I'd want a sample of about 600 to give 30 or so bots.
But then there's the question of how the 100 (or 600) are chosen. If they're weighted towards the early days bot accounts might be rarer than if they're weighted to more recent times. Ideally the age and geographic distribution should at least resemble that of accounts as a whole. If we don't know something about the sampling process the results don't mean too much but maybe that's too much of a complication for Wall Street.
Biting the hand that feeds IT
