Global equity prices and the dollar slid for the second straight day on Wednesday, while safe-haven assets such as gold rallied as investors shunned risk in response to signs the U.S. presidential race was tightening just days before the vote.
Uncertainty about the outcome of the election pushed U.S. Treasury yields lower, while crude oil prices slumped on data showing a record U.S. crude stock build that stoked worries about a global supply glut.
Investors were beginning to rethink their long-held bets of a Nov. 8 victory for Democratic candidate Hillary Clinton amid signs her Republican rival Donald Trump could be closing the gap, deepening the recent decline across major stock markets.
Weakness on Wall Street, on the heels of falling Asian and European stocks, sent MSCI's 47-country "All World" index <.MIWD00000PUS> down 0.65 percent, close to a four-month low.
While Clinton held a 5 percentage point lead over Trump, according to a Reuters/Ipsos opinion poll released on Monday, some other polls showed her Republican rival ahead by 1-2 percentage points.
"The main driver for today is concerns regarding the election. It looked like Clinton was going to win and now that Trump is gaining momentum, it's making people nervous," said Neil Massa, senior equity trader at Manulife Asset Management in Boston.
A Reuters equity market poll last month showed a majority of forecasters predicted that U.S.stocks would perform better under a Clinton presidency than a Trump administration.
U.S. stocks stayed weak in choppy trading after the Federal Reserve kept interest rates unchanged but signalled it could hike in December.
In its last policy decision before the U.S. election, the central bank said the economy had gained momentum and job gains remained solid, and expressed more optimism that inflation was moving toward its 2 percent target.
"The Fed is teasing investors by inserting language to suggest they need just a little bit more evidence of progress towards its objectives," said Brian Jacobsen, chief portfolio strategist at Wells Fargo Funds Management in Menomonee Falls, Wisconsin.
The Dow Jones industrial average <.DJI> fell 49.38 points, or 0.27 percent, to 17,987.72, the S&P 500 <.SPX> lost 10.74 points, or 0.51 percent, to 2,100.98 and the Nasdaq Composite <.IXIC> dropped 37.75 points, or 0.73 percent, to 5,115.83.
European shares fell for the eighth straight day on worries related to the U.S. election and a drop in container shipping firm A.P. Moller-Maersk
Europe's broad FTSEurofirst 300 index <.FTEU3> closed down 1.2 percent at 1,308.38.
Demand for safe-haven bonds sent U.S. Treasury yields lower and 10-year yields fell to a session low after the Fed statement.
Benchmark 10-year notes
Meanwhile, the U.S. dollar fell against the euro, yen, Swiss franc and sterling on continued nervousness about the outcome of the election.
"People are pricing in higher odds of a Trump victory," said Win Thin, global head of emerging market currency strategy at Brown Brothers Harriman in New York.
The dollar index <.DXY>, which measures the greenback against a basket of six major rivals, was down 0.37 percent to 97.357. The index fell to a more than three-week low of 97.178 earlier in the session.
Crude oil prices slumped hard after U.S. Energy Information Administration data showed U.S. crude stockpiles rose sharply last week as refineries cut output.
Gold rallied to a one-month high as falling stocks and a lower dollar burnished the appeal of precious metals as a haven from risk. Spot gold prices
(Reporting by Saqib Iqbal Ahmed; Additional reporting by Lewis Krauskopf and Sam Forgione in New York and Tanya Agrawal in Bengaluru; Editing by Nick Zieminski and Andrew Hay)