“As institutional investors, we’re always concerned when the retail investor is actually arriving in the market,” Skiming, who helps manage $10 billion at Ashburton, said by telephone from Jersey, the Channel Islands. “The retail investor arrives when they can only see blue skies.”

For Laszlo Birinyi of Birinyi Associates Inc., stocks have entered what he calls the exuberance phase, the last of four stages usually seen in bull markets. He still sees more gains to come, citing the skepticism on Wall Street as a sign that plenty of investors haven’t bought shares yet. He expects the S&P 500 to keep advancing as bears capitulate and pick up stocks.

The track record of equity strategists as a whole shows the difficulty in predicting stock prices. About half of the time, the S&P 500 ended the year more than 10 percent away from the average level predicted by strategists in January, according to data compiled by Bloomberg since 1999.

Durable, Sustainable

“This is a durable and sustainable bull market,” Birinyi said in a July 9 phone interview from Westport, Conn. “It’s going to surprise us because I still don’t think we’ve got to a point where water is boiling yet.”

Birinyi, one of the first analysts to advise clients to buy when stocks were bottoming after the 2008 financial crisis, predicts the S&P 500 will rise 6.7 percent to 2,100 by December.

Goldman Sachs Group Inc. raised its S&P 500 forecast today to 2,050 from 1,900. Rising earnings and faster economic growth will push equities higher and stocks are still attractive to bonds, according to a research report from David Kostin, chief equity U.S strategist at the bank.

Wall Street strategists are more cautious with forecasts implying the S&P 500 will rise 0.5 percent by year-end to 1,978, the average from a Bloomberg survey of 19 investment firms.

Set Back

The end of economic stimulus from the Federal Reserve will lead to more stock-market volatility and lower returns, according to Julian Emanuel, a U.S. equity and derivatives strategist with UBS in New York. Minutes released last week from the Fed meeting in June showed officials agreed they’ll end their asset-purchase program in October if the economy holds up.