The Dow Jones Industrial Average (INDEX: ^DJI) wasn't feeling good today. After Alcoa's (NYSE: AA) so-so earnings report and Chevron's (NYSE: CVX) announcement that third-quarter earnings will be much lower than previously expected, the Dow dropped by more than 128 points during today's session. These two companies had a major effect on the markets and dragged a number of other companies lower. Three other organizations that moved lower based on the negative comments made were Boeing (NYSE: BA), Caterpillar (NYSE: CAT), and ExxonMobil (NYSE: XOM).

So why are they down?
On a day when Boeing shareholders received good news from Europe that the BAE and EADS merger fell through, the stock still slid lower by 0.42%. The aircraft manufacturer even received favorable news from the Alcoa earnings release after the aluminum company stated that it is seeing growth in the aerospace market.

Caterpillar saw its shares slide today after Alcoa stated, "In the heavy truck and trailer market, Alcoa is lowering 2012 growth expectations in anticipation of a slowdown across all major regions." Caterpillar traded lower by 1.88% at the closing bell. The equipment manufacturer will report its third-quarter earnings on Oct. 22.

One company that wasn't affected by Alcoa, ExxonMobil saw its shares decline after its competitor, Chevron, warned investors that its third-quarter earnings will be substantially lower than previously expected. Two items that Chevron claimed as the cause of lower earnings that will also affect Exxon where lower oil prices and Hurricane Issac. While Chevron saw its shares decline 4.18%, Exxon experienced a much milder drop of 1.19%.