Western Digital Corp. (NYSE: WDC) is trading up on earnings and guidance. Things were strong enough and valuations are low enough that we have seen two upgrades from analysts. The storage and drive maker’s stock rating was raised to Outperform at Baird and was raised to Buy at Stifel Nicolaus. This is still thin volume as it is a specialist-run stock. Shares are up over 3% at $41.91 at 8:35 AM EST, and trading volume is only about 31,000 shares. The 52-week range is $19.50 to $47.44 and the average trading volume is about 5.7 million shares.