AMD (AMD +9.7%) just won't take a breather. Share are now up 42% on the week even though the chipmaker hasn't seen any major news and has been hit with a downgrade. Bernstein speculates enthusiasm about AMD's next-gen console design wins is responsible, but they've been well-known for some time. Is a major short-seller or two covering? Is an activist investor moving in? Regardless, shares are up 57% YTD in spite of a pretty ugly Q1 for PC sales.