James O’Shaughnessy, the fund manager whose study of four-plus decades of stock market returns may be the most extensive ever done, is seeing good times ahead for U.S. stocks.

In an interview with Reuters, O’Shaughnessy says that the S&P 500 is now selling at such depressed levels that it is likely to return 7.3 percent per year — after inflation — from now through 2019. And he thinks there is a “good chance” that the S&P will hit 900 this year.

O’Shaughnessy cites an increase in savings rates and an improved housing market as catalysts for the turnaround.

“The problem with today is everybody’s fighting the ‘Where’s the bottom?’ fight,” he told Reuters. “If you try to keep a relatively longer-term perspective, which is three to five years, you get shouted out. … From our point of view the market is even more compelling than it was when we spoke at the beginning of the year.”

O’Shaughnessy made it clear that the market could still go lower, but he thinks that will just make for more compelling values. “We’re going to have a rotten jobs (report) on Friday,” he said. “We’re going to have other bad news, and you just look at the market in that light as a discounting mechanism. Is it easy? Of course not. It’s horrible. You look at the day to day in the market, and you shake your head and think, ‘Well this is, of course, why there is that thing called the equity risk premium.'”

The data backs up his optimism, according to O’Shaughnessy. The 12 worst 10-year rolling periods since 1926 were all followed by a decade of positive returns. In fact, the first year after the end of those rough decades, stocks returned 25 percent; after three years, 11 percent; and after five years, almost 13.5 percent, O’Shaughnessy said.

O’Shaughnessy says he’s bullish across all sectors, not just one or two. And he thinks people in Treasury bills “are going to get very, very hurt” because of the bubble that has formed there.

Investors can hear more from O’Shaughnessy in his advisor conference call in early February where he discusses opportunities in the current market.