Dick's Sporting Goods stock fell 30% after the retailer had to cut prices to move unsold goods — bad news for the company and a warning sign about shoppers.

• The stock dropped sharply after weak results tied to heavy discounting.
• The company blamed "increased investment into pricing and promotions" — corporate speak for cutting prices.
• The real problem is too much unsold stock sitting in stores.
• Shoppers are pulling back because costs like gas are eating into their budgets.

Outlook: If consumers stay squeezed, more retailers will have to discount and take a hit to profits.