This my 2 cents view. There were some rumers that WDC is doing some changes in its management. Some took it as bad as CFO resignation. stockpickreport.com recommended sell and market was in red. WDC dropped but it was not able to cover fast enough. WDC is a slow mover. Now, the news is out. Nobody resigned. Mercer switched to other most important responsibilities. Mr Milligan become new WDC CFO. He was doing the job anyway. A young guy who has more energy to deal with the numbers. Mercer will be free to plan for WDC future. Good move for WDC.
I am myself completely baffled by the relative movement of the three in the last five days. STX had the worst earnings and forecast and it is flat compared to 10% down for WDC and MXO. WDC declared excellent earnings and relatively decent guidance, got upgraded and yet the stock is down so much with high volume. It seems totally irrational.