What's going on with AMD (AMD +14.4%)? The chipmaker's shares have taken off on volume that's 5x its daily average, even though no major news has hit the wires. Wells Fargo (Outperform) wrote this morning AMD has launched two new chips for its high-end FX desktop CPU line, and that its CPU pricing seems to be stabilizing, but it seems unlikely that's responsible for today's huge move. 16.9% of AMD's float was shorted as of April 15. Update: As SA commenters note, Intel buyout rumors appear to have played a role. Considering the antitrust issues, this rumor is even harder to swallow than the ones about Samsung and Qualcomm.