I buy stocks that I feel will do good in the long term meaning 1 yearish. I bought ARNA and OREX from a post I read on Meso about diet pills, it was a gamble as they did not get FDA approval the first time and the second time I made bank. I had CIGX that I made a bunch on from 2010 - 2012, lots of trades as I rode the coaster and then just dumped and never looked back. Did really well with a bunch of stocks in 2009 when the market tanked, bought as much as I could, AMD, BAC, CITI, ditched them all for a nice hit.
I like Pharmacy stocks, you can make a nice hit even on speculation if the studies are pointing in the right direction. Not sure if I missed the 3D printing stock bandwagon or not, SYSS and DDD have some nice trends, looking for a cheaper one for Medical research purposes though.