S&P 500 closes shy of record; Dow tops 18,000

The S&P 500 stock index inched closer but fell short of an all-time high Wednesday and the Dow closed above 18,000 for the first time since late April amid another push higher for oil prices but fresh worries about the health of the world economy.

The S&P 500 ended up 6.99 points, or 0.3%, to 2119.12. That's less than 12 points from the record close of 2130.82, set just over a year ago, on May 21, 2015.

The broad U.S. stock gauge has gone more than a year without making upward progress. However, after its worst start to a year ever, which knocked it down more than 14% from its all-time peak, it has been in rebound mode and within striking distance of rewriting Wall Street's record books.

Oil prices near level not seen since the summer

Climbing 0.4% for a gain of 67 points was the Dow Jones industrial average, which ended the day a little more than 5 points above the 18,000 threshold. It was the first time the blue chip index closed above that key level since April 27.

Of the three major stock benchmarks, only the Nasdaq composite dipped into negative territory during the day. But it recovered from its morning swoon to end up 0.3% at 4974.64.

The stock market got a lift from the continued rebound in prices of U.S.-produced crude, which settled up 1.7% to $51.23 a barrel. The commodity last closed above $51 on July 15, 2015.

Stocks, however, were dragged down by continuing concerns about the health of the global economy, which has been unable to break out of its low-growth trajectory and dangerously low inflation despite massive stimulus and intervention from global central bankers. The World Bank was the latest economy-tracker to slash its global growth estimate for the year. On Tuesday it trimmed its global growth forecast to 2.4%, down from an earlier projection of 2.9%.

The weaker outlook for global growth put a solid bid under government bonds around the world, especially in Germany, where the yield on its 10-year bond fell to a record low of 0.037% earlier in the trading session before finishing at 0.057%. German bond yields, which move in the opposite direction of price, are falling sharply due to massive buying by the European Central Bank as part of its stimulus program, and a flight to safe assets during a period of economic uncertainty and dangerously low inflation.

Japan's 10-year government bond is already trading in negative territory, with a yield of -0.109%.

"This extreme pricing action in Europe and Japan is, of course, the result of extreme monetary policy accommodation by the ECB and the Bank of Japan in response to economic weakness," Bank of America Merrill Lynch credit strategist Hans Mikkelsn explained to clients in a research note.