Investors could have a busy week ahead. US equities are still feeling the impact of last week's drop, due to concerns over an earlier than expected Fed taper. However, let's put the bad week for stocks in perspective. The S&P 500 was down a total of 1.6% for the week. The benchmark index is still up an impressive 25% for the year. Nevertheless, there's a lot happening this week that could potentially cause the markets to be more volatile than usual. The Senate begins its debate on the budget deal, already passed by the House. More importantly, the big Fed announcement comes Wednesday, with the possibility of a December taper still on the agenda. Finally, the Senate vote on Yellen as the next Fed chief is also set to happen at some point during the week. Plenty of action ahead.