Investors have taken a defensive stance

The stock market has had some ups and downs this year. As of Monday's close, the S&P 500 is actually flat for the year.

But don't be fooled. Investors have been making some big changes in their portfolios.

According to Bank of America Merrill Lynch data, investors have been moving out of cyclical stocks, which are more sensitive to the economy, and into defensive stocks, which tend to be less sensitive to the economy.

This suggests investors are getting increasingly worried about an economic downturn.

"Tech and Consumer Discretionary stocks saw the largest net sales by our clients last week, with sales of the former chiefly due to institutional clients and sales of the latter mainly due to hedge funds," Bank of America Merrill Lynch's Jill Carey Hall said. "Inflows were mostly passive (ETFs saw the largest net buying, led private clients), and Staples and Industrials stocks saw the next-largest inflows."

While this doesn't tell us if the economy is actually going to head into a recession, it certainly suggests that investors are getting a little concerned.