Goldman Sachs, Pepco, Walgreens Boots Alliance, E*TRADE Lead Wednesday's Top Ratings Changes

There has been a lot of action on Wall Street today as analysts have weighed in on their favorite stocks. Below are the most notable analyst upgrades and downgrades:

Goldman Sachs Group Inc

Michael Carrier of Bank of America/Merrill Lynch upgraded his rating on Goldman Sachs Group Inc GS from Neutral to Buy with a $220 price target, representing an almost 22% potential upside from where the stock last closed. The analyst believes there is currently an attractive buying opportunity for Goldman Sachs due to the recent market sell-off. Furthermore, Carrier sees the company as well-positioned to generate growth.

MannKind Corporation

Piper Jaffray analyst Joshua Schimmer downgraded his rating on MannKind Corporation MNKD from Neutral to Underweight and cut his price target from $4 to $1.50, marking almost a 60% downside from where the stock is currently trading. The analyst's bearish downgrade stems from "lackluster" Afrezza scrips. He notes, "Unfortunately it sounds to us that while awareness is high and some patient blogs on the internet describe some very exciting and differentiated results, Afrezza is being viewed as a very niche product."

Tetraphase Pharmaceuticals Inc

Nomura Securities analyst Ian Somaiya downgraded his rating on Tetraphase Pharmaceuticals Inc TTPH from Buy to Hold and dramatically slashed his price target from $54 to $10, marking a 77.6% downside from where the stock last closed. The analyst downgraded the stock "following the announcement that the IGNITE-2 Phase III trial of eravacycline failed to reach its primary endpoint of non-inferiority to levofloxacin in complicated urinary tract infection (cUTI) setting, despite previously reported positive results from the trial's lead-in portion."

Pepco Holdings, Inc.

Paul Ridzon of KeyBanc upgraded his rating on Pepco Holding, Inc. POM from Sector Weight to Overweight with a price target of $25.50, marking a 12.6% potential upside from where shares last closed. The analyst's upgrade stems from his belief that the company's deal with Exelon Corp. will close. He notes, "We believe the market is overly discounting the chances of EXC's proposed acquisition of POM closing. While the unexpected rejection of the deal by Washington, D.C. presents challenges, we believe they are surmountable."

Yingli Green Energy Hold. Co. Ltd. (ADR)

Roth Capital analyst Philip Shen downgraded his rating on Yingli Green Energy Hold. Co. Ltd (ADR) YGE from Neutral to Sell with a price target of $0.50, marking a 13.7% potential downside from where the stock last closed. Shen downgraded his rating after the company issued a "weak" third quarter guidance and significantly lowered its 2015 shipment guidance "despite strong market demand."

Walgreens Boots Alliance Inc

Charles Rhyee of Cowen & Co upgraded his rating on Walgreens Boots Alliance Inc WBA from Market Perform to Outperform and raised his price target from $90 to $104, marking a 15.4% potential upside from where the stock last closed. The analyst cited the recent sell-off as an attractive buying opportunity.

E*TRADE Financial Corp

Evercore ISI analyst Chris Allen upgraded his rating on E*TRADE Financial Corp ETFC to Buy with a price target of $33, marking a 21% potential upside from where the stock last closed. The analyst notes that the company has taken a big leap forward in its ongoing capital story following yesterday's announcement that it will pay down $4.4B in wholesale funding obligations.

Plains GP Holdings LP

Global Hunter analyst Sunil Sibal upgraded his rating on Plains GP Holdings LP PAGP from Neutral to Accumulate, but lowered his price target from $26 to $23, marking a 19% potential upside from where shares last closed. The analyst's upgrade is based on valuation, potential accretion from acquisitions, and asset growth.