While some investors have been concerned about the rapidly flattening yield curve, Charles Schwab Chief Investment Strategist Liz Ann Sonders says history shows such a trend isn’t cause for alarm.

A flattening yield curve means lower profits for banks, which can borrow at lower short-term interest rates and invest at the higher long-term rates. “That said, it may be surprising to learn that, historically, a flattening yield curve has not been a problem for the stock market overall — quite the contrary,” Sonders says in her latest market commentary.

“Since 1962, there have only been 10 other periods when the slope of the yield curve declined this swiftly from such high levels,” she continues. “The S&P 500 averaged a gain of 4% during the initial six-month decline in the yield curve. And during the following three-, six- and 12-month periods, returns were quite robust.”

Click here for a chart that offers details on those previous examples Sonders mentions.