Do you find that breakouts in smaller stocks (ADDV $34mil) like EHTH tend to be more prone to short seller attacks than something like a larger XLNX ($457mil ADDV)?

I have never considered short seller attacks. It is unclear if there is a way to measure short selling besides the monthly data released to the public. Even if there was, I will say that the chart tells the whole story of supply and demand. There is nothing else that needs to be added.