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

Stocks eased back today as a combination of weak earnings reports and concerns out of China forced the Dow Jones Industrial Average (DJINDICES:^DJI) down 54 points, or 0.4%. Markets opened down as a key money market rate in China jumped to its highest level since July, and investors suspected that the People's Bank of China may tighten cash supply to rein in inflation, which could cool off the country's growth. Also, the European Central Bank said it will conduct stress tests on the continent's largest banks, similar to checks run by the Federal Reserve on American banks earlier this year. Though the tests should help prevent future financial crises, banks' inability to pass the tests could shake confidence in Europe.

Stateside, investors were disappointed by poor earnings from Caterpillar (NYSE:CAT)and a slew of semiconductor-makers. Often seen as a global economic bellwether, Caterpillar, which supplies construction and mining equipment around the world, fell 6.2% after missing earnings estimates and again cutting its full-year outlook while the semiconductor sector finished down 3.4% today.

In other stocks making earnings news, Panera Bread (NASDAQ:PNRA.DL) finished down 5.7%, touching its 52-week low at $151.90 in the process. The fast-casual chain fell short in its third-quarter earnings report as poor service led to lost customers. Same-store sales increased just 1.7% in the quarter, against estimates of 2.7%, and the company lowered its full-year EPS guidance from $2.05-$2.11 to $1.91-$1.97. Panera admitted that operational problems were having an effect on performance, saying long lines and inaccurate orders have driven away customers. To solve the problem, the bakery chain said it will add employees and invest in new equipment and technology to improve service.

Competition was also heating up in the delivery wars ahead of the holiday season, as (NASDAQ:AMZN) bumped up its free-delivery minimum to $35, a move that seems to be driven by a desire to convert more consumers to its $79-a-year Prime service. eBay (NASDAQ:EBAY), meanwhile, announced yesterday that it will acquire Shutl, a service that connects online retailers with local couriers that provide same-day delivery, increasing reach to online shoppers. With its rapid warehouse expansion, Amazon is also gunning for same-day-delivery service, a challenging proposition for bricks-and-mortar retailers. We may learn more tomorrow when Amazon reports earnings after hours. Analysts are expecting a $0.09 EPS loss on $16.8 billion in sales.

Retailers making all the right moves
The retail space is in the midst of the biggest paradigm shift since mail order took off at the turn of last century. Only the most forward-looking and capable companies will survive, and they'll handsomely reward investors who understand the landscape. You can read about the 3 Companies Ready to Rule Retail in The Motley Fool's special report. Uncovering these top picks is free today; just click here to read more.

Fool contributor Jeremy Bowman owns shares of Caterpillar. The Motley Fool recommends and owns shares of, eBay, and Panera Bread. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.