The big macro can cause big moves in the market. What does today's headline macro news mean for your portfolio?

What's happening: The U.S. Consumer Price Index rose 0.3% in September, bringing the 12-month change in consumer prices to 3.9%.

In plain English, please: As consumers wrestle with a tough economy and sick job market, the last thing they want to see are rising fast-rising prices. While 3.9% isn't an overly worrisome level, the number has been on a steady rise over the past year.

What's crucial to remember, though, is that the overall price gauge does not mean that prices for everything are rising to a similar extent. Over the past year, food and energy have been huge contributors to the rise, with gasoline prices up 33.3% and grocery prices up 6.3%. Prices in other important categories, such as medical care and housing, have risen less than the headline rate.

Stocks to watch: Higher prices for grocery items reflect some of the efforts by major consumer-goods companies -- such as PepsiCo (NYSE: PEP), Dean Foods (NYSE: DF), and ConAgra (NYSE: CAG) -- to raise prices to recoup higher costs that they've been facing. While the higher prices may not be welcome news to consumers, it could be good news for these companies -- providing sales volumes don't drop as a result.

Also of note, the prices for used cars fell 0.6% in September but are still up 5.1% from last year. This could be a positive for companies like CarMax (NYSE: KMX) and AutoNation (NYSE: AN).

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