I'm not a current holder of this stock. Just been getting a feel...

I'm not a current holder of this stock. Just been getting a feel for the business from the company's website, and there appears to be a lot of future upside with some pretty encouraging recent announcements. Despite this, the SP chart this year has performed rather poorly by comparision. Looking to buy in at the bottom, which some here suggest might be here or maybe a bit lower, so can someone please explain to me why this stock has failed to run up for any extended period? Is there a particular shareholder continuing to sell down?