Greek Prime Minister Alexis Tsipras has called for a surprise referendum for July 5, the exact details to be worked out in an emergency parliamentary session Saturday (today). The Greek people will be asked to vote yea or nay on further austerity (of the sort required in order to remain in the Euro); so yes, this is essentially a referendum on Grexit. (A Greferendum, or maybe a Grief-erendum, as the case may be.)

The question is whether Greece can hold together, financially, politically, and otherwise, for a full 8 days. A lot can happen in 8 days.

A lot will happen.

Greece needs daily Emergency Liquidity Assistance (of around a billion Euros a day) to keep its banks open. This is something ECB has been approving every week, until now; but if ELA is lifted, the banks would likely close. Suddenly. Bank holiday until further notice.