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.

The euphoria that overtook the market yesterday afternoon was short-lived, and both the Dow Jones Industrial Average (DJINDICES:^DJI) and S&P 500 (SNPINDEX:^GSPC) snapped back to reality today, losing 0.2% and 0.14%, respectively, as of 3:20 p.m. EDT. The good news is that economic reports were mildly positive today, with existing-home sales up in August and unemployment claims near recent lows (read more about today's economic reports here).

Disney's (NYSE:DIS) stock dropped 2.1% today after the company announced a delay to Pixar films' The Good Dinosaur and Finding Dory. The Good Dinosaur was moved back from May 2014 to November 2015 after Disney removed the film's director last month. That means 2014 will be the first year in nine years that we won't have a new Pixar film. Overall, the box office lineup is looking light, but keep in mind that Disney still has the best assets of any movie studio. Delaying a film or two for a year isn't the end of the world, especially if the final product is improved in the meantime, but it will likely ding earnings in the short term. That's no reason to sell this media powerhouse, especially given the consistent revenue streams Disney has with theme parks and cable networks. 

JPMorgan Chase (NYSE:JPM) is the other big news-maker on the Dow today, falling 1.4%. The company agreed to pay $920 million in fines to regulators in the U.S. and the U.K. over the "London Whale" trading losses -- a big hit, even for a company JPMorgan's size. The company also admitted that it failed to oversee trading that led to the $6 billion loss. 

The whole London Whale fiasco should shed some light on the fact that investors don't really know what they're getting when they buy a big bank. A bank's balance sheet is like a black box, and we found out during the financial crisis that even CEOs don't often understand the risks associated with the assets they own. Tread carefully in bank stocks, because the next banking crisis is coming -- you just don't know when it will hit or what will cause it.

Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool recommends Walt Disney. The Motley Fool owns shares of JPMorgan Chase. and Walt Disney. 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.