A flurry of meetings across Europe are taking place as leaders involved in the crisis grapple with a volatile, high-stakes situation. Key meetings include those between German Chancellor Angela Merkel and French President Francois Hollande, but also key Greek creditor, the European Central Bank's governing council.

Perpetual's head of investment strategy Matt Sherwood said the successful 'No' vote may prove to be Greece's point of no-return, if the banks fail to re-open due to a capital crunch that the previous "lenders of last resort", the European Central Bank and the International Monetary Fund, may be unwilling to assist.

"Consequently, there are only two options: the central bank of Greece could make unsecured loans to Greek banks, although this would break ECB rules," Mr Sherwood wrote in a note to investors.

"Alternatively, it can create a new currency and exit the European currency union, which might lead to a rapid currency depreciation which would boost growth, but underpin a surge in inflation and a permanent reduction in living standards. Consequently, it might be the case here that the cure is worse than the disease."

Barclay's analyst Francois Cabau said the "No" vote most likely meant Greece would leave the eurozone's shared currency but this could be avoided.

"We see two possibilities, even if both are less likely than an exit. Europe and Greece could agree on a program on the IMF's terms. A more disruptive scenario would be one in which financial and macroeconomic conditions rapidly worsen and social unrest could result in a political crisis, yielding a more moderate pro-deal government."

Instead, Barclays is one of many investment banks anticipating an exit. It anticipates credit assets will be weak in the short term, bond yields to climb in peripheral bonds such as Italy and Spain, and the euro to be hit hard.

"The now high probability of Greece leaving the European Monetary Union is unambiguously negative for the euro in the near term as foreign exchange markets reassess the stability of the currency union and the prospect of more accommodative ECB action. We recommend staying short euro against the US dollar and against the Japanese yen," Mr Cabau wrote in a note to investors.

Equity markets and bond markets are also likely to be hit, particularly in Europe where equity markets will almost certainly descend sharply upon opening. There is also likely to be a flight to safety towards US Treasury bonds, German bunds and gold.

Westpac economists said the US Federal Reserve was less likely to raise rates in September with risk aversion likely to boost the US dollar. This has ongoing repercussions for the global economy and Australia.

They are also expecting bearish credit markets, and the euro and the Australian dollar to fall as investors head towards the US dollar in a flight to safety.

"Contagion remains the key concern," Barclays analysts said.

"The direct exposure of other EMU member states and the Eurosystem amounts to 3.5 per cent of euro area GDP, while exposure of European banks to Greece has fallen to less than one-tenth of that. Even with low recovery values, direct losses should be manageable."

Another key event will be the response of the European Central Bank's governing council, which is due to meet on Monday. The ECB is unlikely to immediately cancel the emergency funding to sustain Greece's struggling banks but Barclays analysts say it will be shut down by July 20 when another 4.2 billion euros are due, pitching the banks towards default as they rapidly run out of cash.

Commonwealth Bank analysts concur further external financial assistance is unlikely.

"The odds of Greece defaulting on upcoming debt obligations is high and the probability Greece exits the eurozone is rising."

If the emergency funding is cut off, Greece will need to scramble towards a new currency. Currency printing firms, such as Britain's De La Rue, which prints 150 currencies, are believed to have been contacted, reports The Telegraph.

The lack of funding will cause a liquidity crunch for the banks, which could rapidly turn into a solvency crisis. This could force the Greek government to begin transitioning to a new currency as well as issuing state IOUs in lieu of cash to keep the banks afloat and the public service functioning.

A new Greek drachma would face downward pressure from inflation and decline steeply after its first issuing.

While it would enable Greece to exercise some control in the financial markets and provide much needed liquidity to the banks and help boost demand, a new currency would likely rupture the existing financial framework as domestic and trans-national personal and business loans would need to be re-denominated.