MSCI's world equity index <.MIWD00000PUS>, which tracks shares in 47 countries, has returned more than 24 percent this year including dividends, and looks set for a record 14th month of gains. The index added 0.26 percent on Thursday.
U.S. stocks closed higher, too, even as a weakening dollar suggested lingering doubts about the market's upward trajectory.
The Dow Jones Industrial Average <.DJI> rose 63.21 points, or 0.26 percent, to 24,837.51, the S&P 500 <.SPX> gained 4.92 points, or 0.18 percent, to 2,687.54 and the Nasdaq Composite <.IXIC> added 10.82 points, or 0.16 percent, to 6,950.16.
Equity markets have feasted on a global economic growth recovery and accommodative monetary policy in 2017, which has, in turn, lifted company earnings and commodity prices.
"The dominant story right now is that the global economy continues to chug along, and while there are lots of risk scenarios out there, none of them seem to matter," said David Lafferty, chief market strategist at Natixis Investment Managers.
Copper futures were at new four-year highs <CMCU3> for an annual gain topping 30 percent, and the metal rose 0.64 percent to $7,286.50 a tonne on Thursday.
"Commodities are driving trade in the final days of 2017," analysts at London Capital Group said in a note.
"Dr Copper is telling us we could be in for a strong 2018," they added, referring to the industrial metal's reputation for diagnosing economic conditions.
But the U.S. dollar appears to be coming to a different conclusion.
The dollar index <.DXY>, which tracks the greenback against a basket of major world currencies, fell 0.4 percent and was at four-week lows.
Many investors predicted the dollar would get a boost from U.S. tax cuts, tighter central bank monetary policy and strong growth rates in 2017. Instead, the currency fell more than 9 percent over that period.
"The dollar bears are getting their last licks in for 2017, perhaps a foreshadowing of things to come in 2018," said Stephen Innes, head of Asia-Pacific trading at OANDA.
COMMODITY-LINKED CURRENCIES RISE
Oil prices, meanwhile, are near 2-1/2-year highs <LCOc1>, natural gas futures <NGc1> rocketed 7 percent higher and gold climbed to a near-one-month top <XAU=>.
With the dollar on the backfoot and commodities flying, currencies of commodity-exporting countries such as Canada <CAD=D4>, Australia <AUD=D4>, New Zealand <NZD=D4> and South Africa <ZAR=D3> hit multi-week highs.
Dollar weakness also helped give another boost to emerging markets, where stocks are up 34 percent this year and on pace for their best performance since 2009. [EMRG/FRX]
MSCI's emerging market stock index <.MSCIEF> surged 0.79 percent.
Another tailwind for world stocks is the fact that U.S. tax cuts, which will lead to higher borrowing, have not so far translated into greater borrowing costs.
In fact, U.S. 10-year Treasury yields have retreated after briefly breaking above the 2.50 percent level last week. Benchmark 10-year notes <US10YT=RR> were last down 5/32 in price to yield 2.4305 percent, from 2.412 percent late on Wednesday.
There was some modestly downbeat economic news. The number of Americans filing for unemployment benefits was a bit higher than consensus estimates, according to seasonally adjusted figures published by the Labor Department on Thursday.
JPMorgan Chase & Co economist Daniel Silver said in a note that the number "could be a signal that conditions in the labour market have deteriorated."
U.S. consumer confidence data released on Wednesday also came in below consensus estimates.
(Additional reporting by Sujata Rao, Swati Pandey, Abhinav Ramnarayan and Kit Rees; Editing by Bernadette Baum and James Dalgleish)
By Trevor Hunnicutt