Analysts say extreme movements in share prices are likely to continue as investors globally remain jittery about the financial position of some countries and signs of a slowing international economy.
The New Zealand share market was down 5.5% by Tuesday, but clawed back some losses to shed 2% by the end of the week, partly due to solid earnings results from some companies.
But ASB Securities broker Andrew Kelleher says overseas factors drive the market's direction and further swings are likely.
The Standard & Poor's 500 index in New York has fallen on 11 of the past 15 days and 12% in three weeks.
Analysts say it reflects slowing growth in Europe and the United States and a perception that debt-laden governments are running out of options to help boost flagging economies.