Analyst Update: American Airlines Group Inc, EXACT Sciences Corporation, and Yahoo! Inc.

Analysts are weighing in on air carrier American Airlines Group Inc (NASDAQ:AAL), molecular diagnostics specialist EXACT Sciences Corporation (NASDAQ:EXAS), and tech stock Yahoo! Inc. (NASDAQ:YHOO). Here's a quick roundup of today's brokerage notes on AAL, EXAS, and YHOO.

• AAL has hit technical turbulence, down 3.8% at $29.31, following a downgrade to "underperform" at BofA-Merrill Lynch. Also potentially adding to the headwinds are questions surrounding management's aggressive stock buyback activity. Whatever the case may be, this is more of the same for American Airlines Group Inc, which has lost nearly 31% year-to-date, and earlier touched an annual low of $29.02. This could force even more bullish brokerage firms to turn tail on the struggling stock. After all, 75% of covering analysts consider AAL shares worthy of a "buy" or better assessment.

• EXAS is burning up the charts this afternoon, up 18.8% at $11.08. Sparking the rally was an upgrade to "buy" from "hold" at Craig-Hallum, which also lifted its price target to $18 from $6. Just yesterday, the stock received some bullish brokerage attention, and saw the U.S. Preventive Services Task Force make potentially favorable changes to its colorectal cancer screening classifications. Right now, EXACT Sciences Corporation is easily on track for its highest close of 2016, and short sellers could be in trouble. Specifically, over 21% of the stock's float is sold short, which would take just over three weeks to buy back, at EXAS' usual trading rate.

• YHOO has dipped 0.5% at $37.12, despite last night's upgrade to "buy" from "neutral" at Citigroup -- which likewise boosted its price target to $43. Longer term, the shares have been churning in the $36-$38 range since late March, with its core assets on the auction block -- and fetching strong interest from a number of notable companies, including Twitter Inc (NYSE:TWTR). At the same time, bullish betting has heated up in Yahoo! Inc.'s options pits. Across the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), traders have bought to open 3.96 calls for every put over the last two weeks -- a ratio that outstrips nearly three-quarters of all others from the prior year.

For other stocks in analysts' crosshairs, read Analyst Upgrades: Advanced Micro Devices, Inc., Amazon.com, Inc., and Relypsa Inc and Analyst Downgrades: Cavium Inc, Blackberry Ltd, and Jabil Circuit, Inc.