Why Arista Networks, Dropbox, and MBIA Slumped Today

The stock market finished lower on Friday, with triple-digit losses for the Dow Jones Industrial Averageand modest declines of as much as half a percent for other major benchmarks. A mix of economic and political news kept investors on their toes to end the week, as fears of a possible attack on Syria watered down some of the potential upside that could have stemmed from solid earnings results from the banking sector during the morning.

Even though many investors have pretty positive expectations going into earnings season, some companies suffered from disappointing news that sent their shares lower. Arista Networks (NYSE: ANET), Dropbox (NASDAQ: DBX), and MBIA (NYSE: MBI)were among the worst performers on the day. Here's why they did so poorly.