U.S. stocks had their biggest rally in a year yesterday. The S&P 500 has now recovered in a blink: a 4.1 percent rise since Oct. 15, reversing a 7.5 percent drop.

Bummer. Long-term investors barely had a chance to jump on one of the market’s best buying opportunities in years. They've been waiting for discounted stocks for a long time. The S&P 500 hasn’t had a bargain bin since a couple brief drops in 2012. Neither met the definition of a correction, a drop of 10 percent or more. The last extended double-digit declines were in 2011.

“I love bear markets,” says Julie Werner, a 61-year-old amateur investor from Warner Robins, Georgia. Unfortunately, stocks’ biggest declines were on Oct. 15 when she was two hours away in Atlanta, shopping and visiting friends and family. “All day [I was] really regretting I wasn’t at home to put some buys in.” She did buy a couple days later, but by then markets were recovering quickly.

Falling stock markets may stress out traders and threaten the bonuses of executives and professional investors. Even cool-headed portfolio managers can risk their jobs or reputations buying into a market crash.

But regular investors, especially those saving for retirement, have an advantage over the professionals. It's not rocket science: They can afford to be patient. By buying in good times and bad, they benefit from gradually rising markets. And it’s the bad times that deliver the most oomph to their portfolios. By buying extra when stocks drop – as Werner did in 2008 and 2009 – they’re following the advice of a dozen Warren Buffett quotes, like: “Be fearful when others are greedy, and greedy when others are fearful."

David Fuller's view

I certainly do not think that we have seen the last good buying opportunity, and Wall Street is little changed this year, considerably underperforming a number of the Asia Pacific stock markets in USD terms.