The advance that pushed the Standard & Poor's 500 Index to a record left companies trading closer to analyst price estimates than any time in at least seven years.
Shares in the index are five per cent away from analysts' mean forecasts after the benchmark gauge rallied by 10 per cent in the first quarter, according to data compiled by Bloomberg starting in 2006.
That's the smallest difference ever for the median stock and compares with the historical average of 14 per cent.
Bulls say the narrowing spread shows securities firms were caught off guard by the rally and that equities will climb as they boost predictions.
Bears say the slowness of analysts to respond means stocks have gotten so far ahead of themselves that even market optimists are uncomfortable with the increase, which has added more than $10tn to values since 2009.
"The market has moved so fast, it has not given the analysts time to re-evaluate things," Malcolm Polley, who manages $1.1bn as chief investment officer at Stewart Capital Advisors LLC in Indiana, Pennsylvania, said in a March 26 phone interview.
"As we just finished earnings season and we are winding down the first quarter, analysts will begin the process of reassessing. My sense is we're looking for better economic and corporate things than we are seeing."
The S&P 500 rose by 0.8 per cent to 1,569.19 last week, passing the previous all-time high of 1,565.15 from October 2007, after better-than-estimated durable goods orders and the biggest increase in home prices in almost seven years.
Stocks have gained 10 per cent in 2013, compared with increases of four per cent in the dollar, 0.6 percent in commodities and 0.6 per cent gain in global bonds, according to data compiled by Bloomberg. The S&P 500 added 0.1 per cent to 1,570.06 New York time.
