The tech-heavy index crossed the 10,000 mark for the first time, Reuters noted, and closed at a fresh record high for the second day in a row, at 9,953.75.

European markets were muted, the S&P 500 finished down 0.78% while Australia's S&P/ASX 200 closed up 2.44%.

The gold price has risen to US$1,715 an ounce on the spot market ahead of the US Federal Reserve's Federal Open Market Committee wrapping up a two-day policy meeting today, with investors awaiting remarks on the state of the economy.

Gold miners enjoyed gains in Toronto, where Barrick Gold (TSX: ABX) rose 3.65% and Centerra Gold (TSX: CG) closed up 5.76% after the producer was upgraded to outperform by CIBC Equity Research.

PolyMet Mining (TSX: POM) shot to a one-year high intraday of C$1.30 on no news, before closing up almost 74% to 66c.

Its last update on May 7 said it had received favourable decisions in six court cases challenging approvals for its NorthMet copper-nickel-precious metals project in Minnesota, with five still pending.

Elsewhere, precious metals producer Fresnillo (LSE: FRES) rose 3.83% in London.

Freeport-McMoRan (NYSE: FCX) finished up just 0.18% despite the copper price strengthening.

SHFE copper touched 46,400 yuan yesterday - the highest since February 20, Marex Spectron's Anna Stablum said from the LME desk (Singapore).