Take a look at some of Wednesday's midday movers:
Tesla Motors - Shares rose 2.9 percent after Baird maintained an outperform rating and $245 price target, saying investors should buy on any weakness.
Target - The discount retailer fell 0.1 percent after consulting group Kantar Retail reported Target's traffic dropped 33 percent in January from the year-earlier period.
Zogenix - Shares dropped 23 percent on news Purdue Pharma was moving ahead with an abuse-resistant rival to Zogenix's much-criticized painkiller Zohydro.
Fannie Mae - Shares fell 17 percent and Freddie Mac slid 20 percent, continuing a decline that started after leaders of the Senate Banking Committee announced plans to eliminate both of the U.S.-owned mortgage financiers.
General Motors - Shares of the auto manufacturer fell 0.5 percent. GM is offering free loaner cars to owners of compacts being recalled for ignition trouble related to 13 deaths.
Walgreen - Shares of the drugstore chain rose 0.9 percent after UBS increased its price target to $90 from $67.
Geron - Shares dived 61 percent after the FDA put a clinical hold on the drug developer's lead drug due to liver-safety concerns.
Berkshire Hathaway - Shares rose 0.2 percent after Warren Buffett's company agreed to swap most of its long-time investment in Graham Holdings for a Miami television station and other assets.
Nu Skin Enterprises - Shares rose 10 percent on rumors it struck a deal with China.
3D Systems - Shares of the printing company fell 1.3 percent after BofA/Merrill Lynch cut its price target to $60 from $65.
CSX - The rail operator dropped 0.8 percent after it warned bad weather would cut first-quarter earnings by 10 cents a share.
PulteGroup - Shares fell 2 percent, Toll Brothers dropped 1.6 percent and William Lyon Homes rose 0.6 percent after Credit Suisse downgraded all three homebuilders to neutral from outperform.
American Eagle Outfitters - Shares dropped after Morgan Stanley downgraded the clothing retailer to underweight.
Consolidated Edison - Shares fell 1.1 percent after the utility was called to the site of a deadly New York City building explosion to check for a possible gas leak.
Synta Pharmaceuticals - Shares declined 14 percent fell after two brokerages downgraded the drug developer after the company said it would take longer-than-expected to complete a trial for its lead cancer drug.
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—By CNBC's Rich Fisherman.
Questions? Comments? Email us at marketinsider@cnbc.com