Discount retailer Family Dollar Stores Inc. (FDO) reported its fiscal second quarter results this morning, topping analyst estimates and sending the stock higher in premarket trading.

For the quarter, Family Dollar reported it earned 98 cents per share, topping analyst estimates by a penny. During the same period last year, the company earned 81 cents per share.

Warren Buffett invested $232 million in BYD (BYDDF), a Chinese auto maker during the financial crisis, as reported by Reuters. As of December 2010 Buffett's 225 million shares were worth $1.18 billion. In 2009, the shares were valued at just under $2 billion. So from 2009 to 2010, Buffett's Berkshire Hathaway (BRK.A) lost about 40% of his investment.

But that is just the beginning. Now there is criticism surrounding the new Chinese car, dubbed the hybrid car F3DM.They center around two major areas, authenticity of the design and the overall workmanship of the car itself.

Investors spend most of their time looking for a great stock, anxious to buy one before others discover what they have. But equally important is knowing when to sell or when not to buy a stock. Here are a few red flags that stocks wave, no matter how good their numbers.

Dividends Are Very High. Stocks paying a dividend are a smart part of any portfolio. But when those dividends are much higher than average payments from companies in their industry, that's a problem waiting to happen. For example, if the average payment from the utility sector is 4% and the one you own is paying 10%, most likely the company's in trouble. Investors are selling the stock for a reason, making the dividend go ever higher (yield is: annual dividend/price ... the lower the price, the higher the yield). Sometimes the reasons for selling aren't known but become apparent after the quarterly earnings report. Or an announcement is made such as losing a contract that explains the downward pressure.

While investing can be as complicated as you'd like to make it (stochastics anyone? perhaps collateralized debt obligation swaps instead?), the basics are very simple, especially for stock investors. Here are a few questions you can consider before buying or selling any stock.

1. Does the company sell anything? Laugh all you want, but this one question (and its answer) can save you lots and lots of money ... and grief. If you look at most biotech companies, they don't sell anything except hope. They have no revenues, but their stories are fantastic. Investors can get carried away with the promise (not the revenues or profits) of these sometime miracle producers. Most often, the promise turns to pffffft; the stock goes to zero. If a company doesn't have revenues, it doesn't mean you don't buy it (though you should have very good reasons), it only means you buy very little of it ... if you must, and you can't help yourself, and you've temporarily lost your investing compass.

Thursday morning, Piper Jaffray downgraded GameStop (GME) to neutral from overweight, cutting the firm's target price to $16 from $24 in the process.

The brokerage stated, "Each month it becomes more evident that interactive game sales are shifting from packaged goods to digital. Packaged goods game sales have declined from ~85% of category sales to ~70% during the past two years." This shift to digital entertainment should continue as the game cycle continues to plateau and decline during the next three years.

Bright and early this morning, Campbell Soup Co. (CPB) lowered its forecast for fiscal 2010 sales. The company now expects sales to grow 2.5% to 3.5% during the current fiscal year, down from its previous projection for sales growth of 4% to 5%. However, earnings for 2010 are still expected to rise 9% to 11% on an annualized basis from $2.21 per share in fiscal 2009.

Campbell also announced this morning that it's launching "a comprehensive plan to boost the performance of its condensed soup portfolio" in the U.S. More than 60% of the company's condensed line will be spruced up with product improvements, sodium reductions, updated packaging, and a fresh marketing approach.

According to Bloomberg, General Motors (GRM) is close to announcing a deal to sell its Saab division to Spyker Cars. A person familiar with the matter said that an announcement could come as early as late afternoon in Sweden. In Amsterdam, trading was suspended on the automaker amid the rumors.

Spyker has offered GM roughly $75 million in cash and $325 million preferred shares in Spyker, which would come from the transaction. Reportedly GM would receive $100 million of Saab's existing liquidity.

From his apartment in 1999, Marc Benioff started a new-fangled software company, Salesforce.com (CRM). While there have been some missteps along the way, the company is a model of success. Today, Salesforce.com generates more than $1 billion in sales, is profitable and has a market cap of $9 billion.

How did Marc do it? Well, now we have a chance to find out. That is, he has written an excellent book about his experiences and strategies, called Behind the Cloud: The Untold Story of How Salesforce.com Went from Idea to Billion-Dollar Company -- and Revolutionized an Industry.