Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

Despite an economy that never seems to gain steam, consumers are spending like we're back in boom days again. The Department of Commerce's retail sales report shows another sign of consumer strength, with overall sales up 0.2% in July, or 0.5% when you exclude auto, gas, and building materials. The confidence may not make sense on the surface, but falling layoffs, rising stock markets, and swelling home values give consumers a sense of confidence that's helping to drive figures higher.  

Stock markets didn't spike on the positive news, but shares are trading higher this afternoon. As of 3:15 p.m. EDT the Dow Jones Industrial Average (DJINDICES:^DJI) is up 0.28%, while the S&P 500 (SNPINDEX:^GSPC) has gained 0.33%.

Hewlett-Packard (NYSE:HPQ) is pacing the Dow's gains today, rising 1.9%. Analysts from both Citibank and Morgan Stanley released positive reports on the company, predicting an earnings beat next week and citing "identifiable positive catalysts for the stock." There's no doubt that HP has an opportunity to be a great investment at 7.4 times next year's earnings estimates, but each of its businesses is in decline, and unless the company can make a splash in tablets or smartphones, I see a value trap coming.

Boeing's (NYSE:BA) shares are also up 1.9% after the company delivered its first 737-800 to Iraqi Airways. This is the first of 30 aircraft ordered in 2008 and 39 total that the company has on order. Boeing has gotten a lot of bad press because of its problems with the 787 Dreamliner, but its stock is up 43% so far this year, so investors are clearly brushing off those problems. Today's announcement was business as usual, but it's a step in the right direction with an especially important customer. 

The big loser on the Dow today is Alcoa (NYSE:AA), which has dropped 1.2%. The stock was the biggest gainer on the Dow last week following a report that China's factory output had increased almost 10% in July, but that's not the kind of fundamental pop that can keep investors engaged. Once investors who buy in on news from China dry up, the stock often sinks back to prior levels. That's why investors should buy stocks based on fundamentals -- not just the news of the day, which can steal the market's attention for a moment but won't drive a stock in the long term.

Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.