One week, we are talking about how well the market did in the 1st quarter, and a couple of weeks later, weakness has entered the market. How quickly the tides can shift. Geopolitical issues and interest rates again spooked the markets this week. 

Pullbacks are normal throughout an investing year and shouldn't cause too much concern with your overall portfolio strategy. You can, however, use these pullbacks to start new positions or put funds back to work if you trimmed while the markets were higher. 

According to the S&P oscillator, the market is currently oversold. It's important to remember that most of the market's best days occur within two weeks of the worst days.