Here are today's top news headlines from Fool.com. Check back throughout the day as this list is updated, and follow us on Twitter at TMFBreaking.

Stock Market Today: Staples' Brutal Quarter and Costco's Weak Holiday

Top Stories in Biotech This Morning: Pluristem Therapeutics, Inc, Rigel Pharmaceuticals, and Sangamo Biosciences,

Ciena Corporation Beats Q1 Earnings Targets but Flubs Q2 Guidance

Costco Drops the Bag, Reports a Steep Decline in Quarterly Profit

Kroger's Profit Tops Wall Street Expectations

China Declares War on Pollution

Darden Cancels Annual Analyst Meeting

Initial Jobless Claims Drop 7.4%

Rite Aid Corporation February Same-Store Sales Up 1.5%

Weak Jobs Market Helps Pull Mortgage Rates Down

What's Driving the Big Spending on Mergers and Acquisitions?

Judge Rules for Samsung in Patent Dispute With Apple

Ford Motor Company's Sales Soar in the World's Largest Automotive Market

Why Pandora Is Down in an Up Market

Why Zogenix Inc. Shares Swooned

Wake Up and Smell the Bacon ... With a Bacon App

Endo Gets U.S. Approval for Long-Acting Testosterone

Dow Closes Up 62; Is the Bond Market Rally Over?

American Productivity Up 1.8% for Q4

Record Fine Proposed for Coal Mining Operations

5 Things to Know About Google's Mystery Barge

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