24/7 Wall St.

Markets were incredibly volatile on Tuesday morning with gains and losses due to international uncertainty and energy price concerns. In the September and October sell-off, investors stepped in over and over to buy value and overlooked stocks that had gone on sale. 24/7 Wall St. reviews dozens of analyst research reports each morning of the week to find new investing and trading ideas for its readers. Some research reports cover stocks to buy, and some cover stocks to sell or avoid.

These are this Tuesday’s top analyst upgrades and downgrades from 24/7 Wall St.

Antero Resources Corp. (NYSE: AR) was started as Outperform at Oppenheimer.

Autodesk Inc. (NASDAQ: ADSK) was downgraded to Underperform from Neutral at Bank of America Merrill Lynch.

Crox Inc. (NASDAQ: CROX) was raised to Buy from Neutral at Sterne Agee.

Dollar Tree Inc. (NASDAQ: DLTR) was downgraded to Hold from Buy at Deutsche Bank.

General Motors Co. (NYSE: GM) was downgraded to Sector Perform from Outperform and the price target was cut to $35 from $41 (versus a $31.00 close) at RBC Capital Markets.

ALSO READ: Credit Suisse Sees Big Upside in 2 MLPs

Green Plains Inc. (NASDAQ: GPRE) was started as Neutral at Goldman Sachs.

GrubHub Inc. (NYSE: GRUB) was raised to Buy from Neutral and the price target was raised to $43 from $42 (versus a $31.74 close) at Goldman Sachs.

MGIC Investment Corp. (NYSE: MTG) was downgraded to Market Perform from Outperform at Keefe Bruyette Woods.

Microsoft Corp. (NASDAQ: MSFT) was downgraded to Underperform from Neutral at Merrill Lynch.

Newfield Exploration Co. (NYSE: NFX) was started as Outperform at Oppenheimer.

Nike Inc. (NYSE: NKE) was started as Outperform with a $110 price target (versus a $95.43 close) at Oppenheimer.

Priceline Group Inc. (NASDAQ: PCLN) was maintained as Buy but was removed from the prized Conviction Buy list at Goldman Sachs.

Ralph Lauren Corp. (NYSE: RL) was started as Market Perform at Cowen.

Rite Aid Corp. (NYSE: RAD) was raised to Buy from Neutral at UBS.

ServiceNow Inc. (NYSE: NOW) was started as Buy at Goldman Sachs. This stock was also named as an RBC top pick on Monday.

ALSO READ: Can Oracle Earnings Keep Tech Stocks Rallying?

Shutterfly Inc. (NASDAQ: SFLY) was downgraded to Neutral from Buy and the price target was cut to $45 from $53 (versus a $41.00 close) at Goldman Sachs.

SunPower Corp. (NASDAQ: SPWR) was raised to Overweight from Equal Weight at Morgan Stanley.

Whiting Petroleum Corp. (NYSE: WLL) was started as Outperform at Oppenheimer.

In case you missed Monday’s top analyst upgrades and downgrades from 24/7 Wall St., they were in shares of ARM, Holdings Exxon Mobil, Ford, Habit Restaurants, Oracle, Twitter, UPS and maybe a dozen more companies.