Investors interested in Medical stocks should always be looking to find the best-performing companies in the group. Is Acasti Pharma (ACST) one of those stocks right now? Let's take a closer look at the stock's year-to-date performance to find out.Acasti Pharma is a member of our Medical group, which includes 1026 different companies and currently sits at #6 in the Zacks Sector Rank. The Zacks Sector Rank includes 16 different groups and is listed in order from best to worst in terms of the average Zacks Ra ...