Gotham Asset Management’s Joel Greenblatt sees better opportunities for value investing on the horizon, based on a recent study by his firm. This according to an article in Institutional Investor.

Using data from the past 30 years, Gotham valued all the stocks in the S&P 500 without adjusting for interest rate changes. The analysis showed that the market has been cheaper for investors about 88 percent of the time and, at similar valuation levels, market returns for the following year averaged two to four percent. The firm also analyzed the Russell 2000 for the same period and found that the market had been cheaper 99 percent of the times, with year-forward market returns of between negative 3 and negative 5 percent.

The upshot, Greenblatt said, is that there is value to be generated.

Veteran value investor Greenblatt cites a positive indicator being the disparity between growth stocks and value stocks—since January 1, he noted, there has been a 5 percent difference between the Russell Growth and Russell Value indexes, and the gap is widening.

“You shouldn’t be able to make money this easy,” Greenblatt argued. “That’s just not likely to happen in the future.” A finance professor at Columbia for over two decades, Greenblatt says, he has always told his students that “if they did good valuation work, the market would agree with them. I just didn’t tell them when.”