NEW YORK — Investors can be forgiven if they give a muted reception to the Dow Jones industrial average’s surpassing its record high close: For those who’ve stayed with the Dow stocks since the index’s January 2000 high, Thursday’s achievement merely recoups the losses of the last six years.

When the Internet bubble burst in 2001, large-cap stocks plummeted alongside the tech sector. In the years since, neither group has truly regained its footing.

The Dow’s passing 11,722.98 may be nice, but the index comprises only 30 stocks. While they have done well, most investors put their large-cap money into index funds that track the broader Standard & Poor’s 500, which, as of Wednesday’s close, was still 12.50 percent lower than it was in March 2000.

The S&P 500’s forward price-to-earnings ratio, a common way of valuing stocks’ expected earnings, is near 14, which some investors see as quite cheap.

“The S&P 500 at 14, that’s a once-in-a-generation buying opportunity,” said Brian Gendreau, investment strategist for ING Investment Management.

“Maybe we should hold off celebrating?” Howard Silverblatt, senior index analyst at Standard & Poor’s, wrote in an email to clients Wednesday.

Seventeen quarters of double-digit earnings growth haven’t managed to interest large number of investors in large-cap stocks, but that performance has made their valuations look especially inexpensive.

“On a number of valuation methods, price- to-sales, price-to-book value and price-to- cash flow, large caps are looking more attractive than they have in the past few years,” said Michael Sheldon, chief market strategist, Spencer Clark LLC.

Because there are only 30 stocks in the Dow, it can be helped to new records by an outsized performance from just a handful of its components.

Dow component Exxon Mobil Corp., for instance, climbed to an all-time high over the summer as oil prices skyrocketed and the company reported record profits. Even as its backed away from those highs, the stock is up 22 percent from its 12-month low.

Similarly, Dow components Boeing Co., Citigroup Inc., Hewlett Packard Co., JP Morgan Chase & Co., Pfizer Inc. and Merck & Co. have risen strongly for the year as business at the companies improved.

That they’ve done well doesn’t change the fact that large-cap stocks, as a group, have been replaced in investors’ hearts by riskier investments — big bets on emerging market companies and small-cap stocks.

While the Dow has gained about 40 percent over the past five years, the Russell 2000 Index of small-cap stocks is up roughly 90 percent.

The rationale behind the switch: How could large caps such as International Business Machines Corp., which had $91.13 billion in revenue in 2005, produce the kind of growth you’d get from, say, a Chinese Internet company?

That thinking hasn’t changed, as inflows into foreign equity funds continued in the two weeks ending Sept. 6, the most recent weeks for which data is available.

During that period, U.S. investors pumped $2.3 billion into international mutual funds and pulled $2.9 billion out of U.S. equity funds, according to Bank of America.

For the year-to-date, big-cap funds have seen outflows of $11 billion, while domestic small-cap funds have had inflows of $9 billion and international funds have had inflows of $45 billion, according to Prudential Equity Group LLC.

“I think that at some time in the not-too-distant future individual investors will recognize the value represented by equities and start to buy large-cap stock funds again as they have not so far this century,” wrote long-time big-cap bull Edward Keon, Prudential Equity Group’s chief investment strategist, in a Sept. 18 note.

“After the bear market of 2000 — 2002, the corporate and investment industry scandals, 9/11, the war, the energy price spike and other natural and man-made disasters, the average U.S. investor has clearly lost the confidence needed to increase big-cap equity exposure,” Keon wrote.

While questions about the economy, energy prices and interest rates overhang the market, the largest question is one that is seldom discussed by strategists day-to-day.

As Keon puts it, the question is this: “When will U.S. investors regain confidence in the U.S. stock market?