History suggests stock investors will make more money the second half of the year.
Since World War II, a big increase in the first half of a year has almost always been followed by more gains in the second half.
In the 68 years beginning with 1946, the S&P 500 index has risen 10 percent or more 23 times, according to data from S&P Dow Jones Indices. During those 23 years, the market rose the second half of the year 19 times. Eleven of those years, or nearly half, the S&P 500 rose at least 10 percent the second half of the year.
The best second half was in 1954, in the middle of the stock market's longest bull run. Stocks increased 26.2 percent July-December. The worst second half was in 1987. The "Black Monday" market crash was Oct. 19, and stocks fell 17.4 percent the second half of the year.
In years like this one, in which stocks have started with a gain of between 10 and 15 percent, the average second-half increase has been 9.4 percent.
Those numbers suggest that when a rally gets going, it keeps going.
Of course, past performance is no guarantee of the market's future, and investors face some hurdles in this year's second half. The Federal Reserve has helped stocks rally by forcing down interest rates. But the central bank is considering reducing that stimulus later this year. Also, concerns about the Chinese economy, the world's second-largest, have unsettled markets in recent weeks.
But the factors that drove the market methodically higher the first five months of the year remain: The housing market is strengthening. Auto sales are strong. Companies continue to earn record profits. Inflation and interest rates are ultra low. The economy is growing moderately and may pick up the second half of the year.
"We're going higher," said Phil Orlando, Chief Equity Strategist at Federated Investors. "Rising stock prices and rising real estate prices are making people feel better about their financial condition ... So we think that second-half GDP and second-half earnings are going to be better than the first half."
Orlando predicts that the S&P 500 will end the year at 1,750.
Although many investors had expected stocks to climb this year, they were surprised at the speed of the advance early on. By May 21, the S&P 500 had climbed to a record 1,669 and was up 17 percent. A day later, Fed chairman Ben Bernanke said the central bank was considering pulling back on its stimulus. The market's advance cooled, and the S&P has lost 3 percent since.
Add dividends to the S&P 500's price rise and the total return for investors is 13.8 percent — the most in 15 years.
"We're not surprised at the positive performance across U.S. equity markets this year because the fundamentals of the economy are improving," says Steve Rees, head of U.S. Equity Strategy for JPMorgan Private Bank. "We were surprised, though, at how quickly we achieved that performance at the start of the year."
Here are the five best first halves for the S&P 500 since World War II. Data before 1957, when the S&P 500 was launched, combine the values for four earlier S&P indices: the industrials, utilities, financials and transportation:
— 1975. First half: up 41.7 percent. Second half: down 3.2 percent.
The 1970s began with a bull run, but things soon went sour. The oil crisis of 1973-1974 caused oil prices to soar and the economy entered into what would be a 16-month recession in November 1973. The annual rate of inflation began to climb. It surged as high as 12.2 percent in November 1974 from 3.4 percent a year earlier. The S&P 500 dropped 48 percent between Jan. 11, 1973 and Oct. 4, 1974.
The market soared in the first half of 1975 as inflation moderated and investors grew hopeful the economy was pulling out of its slump. The market gave up some of its gain in the second half of the year as doubts about the strength of the economic recovery grew and concern rose that inflation might re-emerge. New York City's fiscal crisis also weighed on markets.
— 1987. First half: up 27.4 percent. Second half: down 17.4 percent.
In early 1987, investors were still enjoying a bull run that had begun in August 1982. Unemployment and inflation had fallen. Tax cuts and low interest rates had spawned an economic boom.
But things unraveled in a big way.
Stocks peaked on August 25, when the S&P 500 closed at a record 336. Rising interest rates and concerns about a stock bubble prompted a sell-off in October. That culminated in 'Black Monday' on Oct. 19, 1987, when the index plunged 57 points, or 20.5 percent, to 224.
— 1983. First half: up 22.2 percent. Second half: up 0.25 percent.
In early 1983, the great '80s bull run was just beginning. It had started the previous summer after the Fed lowered its benchmark interest rate from 14.5 percent to 10 percent. President Reagan's tax cuts also got the economy going after it had contracted for much of 1982.
But the surge in stocks stalled in the second half. Investors worried that the expanding economy would revive inflation and compel the Fed to raise rates.
—1986. First half: up 20.7 percent. Second half: down 1.8 percent.
The factors that had given stocks a lift in 1983 were still in play. Also, falling oil prices helped lower the threat of inflation and allowed the Fed to cut interest rates. The price of oil dropped as low as $10.42 a barrel in March, after starting the year at $26.30 a barrel.
— 1954. First half: up 20.6 percent. Second half: up 26.2 percent.
The stock market was on its longest bull run, from 1949 to 1961. In 1954, an improving economy and rising confidence after the Korean War helped stocks. By November, the market had finally returned to its peak before the Wall Street Crash of 1929.