Rising bond yields have been an important factor behind that shift.
The yield on the 10-year Treasury note is near the highest it's been in 13 months following a sharp increase on Tuesday. That's giving investors who want steady income an alternative to dividend-rich stocks like power utilities, consumer staples makers and phone companies. Investors piled into those stocks at the beginning of the year, when bond yields were close to historic lows.
More broadly, after this year's powerful bull run — the Dow Jones industrial average is up 16.8 percent, the Standard & Poor's 500 index 15.6 percent — investors may be running out of reasons to keep plowing money into the stock market.
"There's a vacuum of catalysts to continue to push (stocks) higher," said Sam Stovall, chief U.S. equity strategist for S&P Capital IQ. Now, Stovall said, investors are wondering: " 'Well, should I take some profits and sit on the sidelines and then get back in?' "
Stovall noted that S&P 500 has had a temporary pullback of at least 5 percent every year since the end of the World War II. That hasn't happened yet in 2013.
The Dow closed down 106.59 points at 15,302.80, a loss of 0.7 percent. That decline matched its advance the day before, when it closed at a record high, the ninth time it has done so this month. The Dow was down as much as 179 points in late morning trading, then rose moderately in the afternoon.
The S&P 500 index was down 11.70 points to 1,648.36, also 0.7 percent. The Nasdaq composite lost 21.37 points to 3,467.52, or 0.6 percent.
The S&P 500 is headed for a seventh consecutive month of increases, the longest winning streak since 2009. The Dow is on track to end higher for a sixth straight month.
Investors have been encouraged by positive signs on the economy recently, including sharp increases reported Tuesday in home prices and consumer confidence. Hiring has also been picking up and first-quarter corporate profits hit a record high. Investors worry, however, that the Federal Reserve will start to ease back on its stimulus program as the economy improves.
The powerful run-up in stock prices has been encouraged by the Fed. The central bank has been buying $85 billion of bonds each month in an effort to keep interest rates low and encourage borrowing, lending and investing. With rates low, investors have sought stocks as an alternative to bonds.
Minutes of a Fed meeting released last Wednesday brought news that some policymakers favored scaling back the bond purchases as early as next month, providing the economy picks up. That pushed stock markets to a decline last week, the first weekly drop in five. Those concerns have also led traders to sell bonds, pushing long-term interest rates higher.
"At some point, interest rates will go up and that's obviously having some impact on stocks," said Erik Davidson, deputy chief investment officer for Wells Fargo Private Bank. "And you're seeing it in the sectors that you would expect. The hardest sectors hit recently have been ... the more dividend-driven stock sectors."
Real estate investment trusts, or REITs, another investment favored by investors seeking income, have also been hit as Treasury yields climb. Vanguard's exchange-traded REIT fund has fallen for five straight days, cutting its gains this year to 10.9 percent from 19.7 percent.
Nine of 10 industries in the S&P 500 fell, led by declines of 1.9 percent for consumer staples and 1.5 percent for utilities. In the first three months of the year they were among the biggest winners.
Despite the decline in stocks, it seems too early to call an end to the rally. On several trading days this year, stocks have had sharp sell-offs, only to rise again as investors take advantage of the dip in prices to get into the market.
The Dow fell 1.8 percent April 15 on concerns that a slowdown in China would trip up global economic growth. It has risen 5.5 percent since then. The index also slid 1.6 percent Feb. 25 on concerns that the European debt crisis would disrupt global markets again. The Dow shook off that loss too, and is up 11 percent since then.
The yield on the 10-year Treasury note fell to 2.12 percent from 2.17 percent late Tuesday. The yield surged Tuesday to its highest level in 13 months as investors moved money out of bonds. The yield has risen sharply from 1.63 percent at the beginning of the month.
In another sign of shifting sentiment, a measure of investor's expectations of market volatility has been increasing. The Chicago Board of Exchange's VIX index climbed 2.7 percent Wednesday, its sixth increase in seven days.
In commodities trading, the price of crude oil fell $1.88, or 2 percent, to $93.13. Gold rose $12.40, or 0.9 percent, to $1,391.30 an ounce. The dollar fell against the euro and the Japanese yen.
Among stocks making big moves:
— Smithfield Foods surged $7.38, or 28 percent, to $33.35 after the company agreed to be acquired by meat processor Shuanghui International Holdings for approximately $4.72 billion.
— Stewart Enterprises rose $3.23, or 33 percent, to $12.97 after the funeral company agreed to be acquired by Service Corp International for $1.1 billion in cash.
— Sallie Mae jumped 50 cents, or 2.2 percent, to $23.48. The company, which is formally named SLM Corp., announced a plan to split into two separate companies, one that manages student loans and a consumer banking business.
— Michael Kors Holdings rose $1.97, or 3.2 percent, to $63.95 after the fashion company reported that its profit more than doubled on surging sales in the fourth quarter, capping another strong year.