• Greek banks shut - capital controls coming
• Liam Dann: NZ mostly protected in event of 'Grexit'
Investors are favouring assets such as US dollars, US Treasuries, German Bunds, Japanese bonds and yen, Tuck said.
"You get out of risky assets with small doors and into safe assets with big doors where you know the liquidity is the best," he said. "Markets are going to be volatile. Things could turn on a dime depending on what headlines happen."
Greece's prime minister Alexis Tsipras has declared a bank holiday and restrictions on bank withdrawals after the European Central Bank at the weekend froze the level of emergency funding available to Greek banks. His call for an extension of the country's bailout so Greeks could vote in a referendum on proposed new terms was rejected by its creditors.
In other developments at the weekend, China's central bank cut interest rates to a record low. The People's Bank of China cut the benchmark lending and the deposit rate by a quarter point to 4.85 per cent and 2 per cent respectively. Required reserve ratios for some lenders were also lowered. China is New Zealand's largest trading partner.
While increased liquidity was positive, the move raised concerns about the extent of the slowdown in the Chinese economy, said ANZ's Tuck.
In New Zealand today, the Reserve Bank publishes its foreign exchange transaction data for May.
The New Zealand dollar jumped to 61.91 euro cents from 61.53 cents on Friday, was little changed at 89.13 Australian cents from 89.18 cents, slipped to 43.43 British pence from 43.74 pence. It dropped to a 17-month low of 83.22 yen and was trading at 83.56 yen at 8am from 84.95 yen on Friday.