Market Movers Today: General Mills, Inc. (GIS), Prothena Corporation PLC (PRTA), Twitter Inc (TWTR), Southwest Airlines Co (LUV), and More

General Mills, Inc. (NYSE:GIS) (The Motley Fool)
What happened: Shares of General Mills, Inc. (NYSE:GIS) were tumbling today after the diversified food-maker posted third-quarter earnings and lowered its full-year forecast due to higher freight and commodity costs. As a result, the Cheerios-maker was down 9.9% as of 10:52 a.m. EDT. So what: The parent of brands including Yoplait, Nature Valley, Haagen-Dazs, and Annie’s said overall sales increased 2.3% in the period to $3.88 billion, which topped estimates of $3.78 billion.

Prothena Corporation PLC (NASDAQ:PRTA) (Benzinga)
Prothena Corporation plc rose 12.4 percent to $38.051 after the late-stage clinical biotech company announced a partnership with Celgene Corporation to develop therapies for a broad range of neurodegenerative diseases.

Phongphan/Shutterstock.com

Phongphan/Shutterstock.com

Twitter Inc (NYSE:TWTR) (CNBC)
Twitter shares soared Wednesday after posting their worst session in over two years on Tuesday, and some traders are betting on more gains ahead. Shares of the popular social media company were up 5 percent early Wednesday. They had plunged 10 percent on Tuesday following reports that the company could face new regulation abroad. The social media space has been under pressure this week amid growing investor skepticism over Facebook’s data-sharing scandal.

Proteostasis Therapeutics Inc (NASDAQ:PTI) (MarketWatch)
Proteostasis Therapeutics Inc. PTI, +4.46% shares rose 14.2% in premarket trade Wednesday after the company said it won’t proceed with an equity offering due to “market conditions.” The decision followed the company’s stock being shorted by Kerrisdale Capital, betting that the stock would fall, and which caused shares to tank 26.2% on Tuesday. Proteostasis had previously planned to offer 9 million shares in a public offering announced on March 19.

Mulesoft Inc (NYSE:MULE) (CNBC)
MuleSoft – MuleSoft agreed to be bought by Salesforce.com for $44.89 per share in cash and stock, representing a 36 percent premium over the software company’s Monday close. MuleSoft stock had risen during Tuesday’s session on reports that a deal was near. The total value of the deal is $5.9 billion, excluding assumed debt.

Southwest Airlines Co (NYSE:LUV) (The Motley Fool)
What happened: Shares of Southwest Airlines (NYSE:LUV) slumped on Wednesday after the airline updated its guidance for the first quarter of 2018. The company sees revenue per available seat mile, or RASM, coming in weaker than originally expected. The stock was down about 5.2% at 12:30 p.m. EDT. So what: Southwest now expects first-quarter RASM to be roughly flat compared to the prior-year period.

Winnebago Industries, Inc. (NYSE:WGO) (CNBC)
Winnebago – The recreational vehicle maker reported adjusted quarterly profit of 62 cents per share, 1 cent a share below estimates. Revenue beat forecasts, however, and the company said it saw an increase in sales growth, market share, and profit margin during the quarter.

DXP Enterprises Inc (NASDAQ:DXPE) (Benzinga)
DXP Enterprises, Inc. shares jumped 21.2 percent to $39.70 after the company reported strong quarterly results.

Obsidian Energy Ltd (NYSE:OBE) (The Motley Fool)
What happened: Shares of Obsidian Energy Ltd (NYSE:OBE) rallied on Wednesday, rising more than 13% at 2:30 p.m. EST. Fueling the Canadian oil stock’s gains was a rebound in the price of oil and some public sparring between the company and a large shareholder. So what: Oil prices rallied about 2.5% on Wednesday to more than $65 per barrel — which was their highest level in more than a month — after a closely watched U.S. government report showed an unexpected decline in oil storage levels.