The sharemarket rose 1.2 percent in early trade after the US Federal Reserve enacted another 75 basis point rate cut.
US stocks rang up their biggest one-day gains in more than five years after the Fed's deep interest-rate cut and solid results from two top investment banks reassured investors shocked by Bear Stearns' sudden downfall.
The Fed fulfilled expectations by cutting its benchmark rate to the lowest since February 2005 -- 2.25 percent against New Zealand's 8.25 percent.
Stocks rallied, with the S&P and the Nasdaq closing up more than 4 percent, even though policy makers opted for a slightly less aggressive rate reduction than some on Wall Street were expecting.
The S&P index of financial shares achieved its best day in eight years, climbing 8.5 percent.
There had been fears about the results of other US banks but Goldman Sachs and Lehman Brothers both topped forecasts albeit with lower earnings.
The NZSX-50 Index was up 40.6 to 3459.3 after quarter of an hour.
There were no down red arrows in the top 50.
No 2 stock Fletcher Building sprinted 27c up to 880, No 3 Contact Energy was up 13c to 840 while market leader Telecom was up 2c to 386.
Others to rise included Ryman Healthcare, 8c to 147, Trust Power, 15c to 765, Mainfreight, 22 to 590, Sky City, 8c to 378 and Sky TV, 7c to 475.
Australian banking stocks were strong with Westpac up 70c to 2650, ANZ up 110 to 2500 and AMP up 20c to 830.
In the US, the Dow Jones Industrial Average climbed 420.41 points, or 3.51 percent, to end at 12,392.66. The Standard & Poor's 500 Index rose 54.14 points, or 4.24 percent, to 1330.74. The Nasdaq Composite Index soared 91.25 points, or 4.19 percent, to 2268.26.