This week has been a wild ride, and stocks were looking for direction based on more inflationary concerns after the import prices were hotter than expected. The bull market is now just three weeks shy of being nine years old. No trend can last forever, but the one that keeps proving to be right is that investors have been rewarded handily buying the pullbacks. Now investors still have to decide how they want to be positioned for 2018 and beyond.

24/7 Wall St. reviews dozens of analyst research reports each day of the week to find new ideas for investors and traders alike. Some analyst reports and research reports cover stocks to buy. Other reports cover stocks to sell or to avoid.

Additional color and commentary has been added on most of the daily analyst reports. The consensus analyst price targets and other valuation metrics are from the Thomson Reuters sell-side research service.

These were the top analyst upgrades, downgrades and other research calls from Friday, February 16, 2018.

Acorda Therapeutics Inc. (NASDAQ: ACOR) was raised to Overweight from Neutral with a $37 price target (versus a $25.10 prior close) at Piper Jaffray.

Activision Blizzard Inc. (NASDAQ: ATVI) was reiterated as Buy and the price target was raised to $81 from $70 at Argus.

Aerie Pharmaceuticals Inc. (NASDAQ: AERI) was started as Buy with a $78 price target (versus a $53.65 close) at H.C. Wainwright.

Alarm.com Holdings Inc. (NASDAQ: ALRM) was raised to Outperform from In-Line with a $45 price target (versus a $37.88 close) at Imperial Capital.

Amber Road Inc. (NYSE: AMBR) was downgraded to Hold from Buy with a $10 price target (versus a $9.74 close) at Canaccord Genuity.

Azul S.A. (NYSE: AZUL) was started as Buy at UBS.

Biogen Inc. (NASDAQ: BIIB) was downgraded to Hold from Buy at Argus, with the independent research firm citing a challenging outlook.

Blue Apron Holdings Inc. (NYSE: APRN) was raised to Neutral from Sell at Northcoast Securities. The stock closed down 4.6% at $3.31 on Thursday but was indicated up almost 4% at $3.43 on Friday morning.

Calithera Biosciences Inc. (NASDAQ: CALA) was raised to Buy from Neutral with a $14 price target (versus a $6.95 close) at Citigroup.

Canadian National Railway Co. (NYSE: CNI) was downgraded to Hold from Buy at Argus.

Chesapeake Lodging Trust (NYSE: CHSP) was reiterated as Buy with a fair value estimate of $32 (versus a $26.32 close) at Janney.

Cisco Systems Inc. (NASDAQ: CSCO) was up after earnings and saw multiple analysts raise their target prices. Now Argus has reiterated its Buy rating and raised its target to $50.

ConocoPhillips (NYSE: COP) was reiterated as Buy and the $65 target price (versus a $54.54 close) was maintained at Argus.

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