I find that completley dependant on volume. I prefer to watch stocks with a float that is under 100 million but if a stock has volume that can be impressivly half or more of the float it's worth "watching".

I agree with prasky about the volume, but 20-25M is a sweet spot. You want the ownership of the stock to completely flip during a heavy day of trading. The more times it flips, the higher it will go. By the way, the high float is a key indicator of a shitty management team. It usually means they’ve had quite a few public offerings to keep their doors open.

Agreed, float alone is not enough. It depends on volume, price action and the chart. Also % of shares owned by institutions can indicate whether the price action will be "inorganic" if that makes any sense...

Basically "lower float + high volume". All my scans are on TOS and I filter for less than 40M Shares Outstanding (float + unavailable shares to the public).