Many experts feared that a Greek "no" vote in Sunday's referendum would send the euro reeling amid concern about a Greek exit.

But Brian Kelly of hedge fund BKCM disagrees. "The big trade has been to go long European equities and short the euro," he told CNBC. "As European equities fall, investors will unwind this trade, which means short-covering in the euro."

The Stoxx Europe 600 Index has dropped 1.1 percent Monday. But the euro has slipped only 0.6 percent, to $1.1043

"It is counter-intuitive, but if the strength [of the euro last week] continues, everyone will be wondering why the euro did not fall. This is why," Kelly said. The euro climbed 0.6 percent from Wednesday through Friday.

"The market reaction so far has been remarkably muted," Callum Henderson, global head of foreign-exchange research at Standard Chartered, told Bloomberg. “Most people are standing aside and waiting to see how the European authorities will respond.”

To be sure, many experts say continued quantitative easing by the ECB will push the euro back down. "Confirmation of a 'no' vote would probably raise the chances of ECB support eventually, thereby supporting our view that euro/dollar falls to parity by year-end," said Jeremy Hale, managing director of global strategy at Citibank, according to CNBC.

Meanwhile, Nobel laureate economist Paul Krugman says Greeks did the right thing in voting no. "Even the most ardent supporters of European union should be breathing a sigh of relief," he writes in The New York Times.

Of course creditors don't see it that way. "Their story is that the failure of their attempt to bully Greece into acquiescence was a triumph of irrationality and irresponsibility over sound technocratic advice," Krugman says.

"But the campaign of bullying — the attempt to terrify Greeks by cutting off bank financing and threatening general chaos, all with the almost open goal of pushing the current leftist government out of office — was a shameful moment in a Europe that claims to believe in democratic principles."

Greece owes official lenders 243 billion euros ($268 billion) — mostly eurozone members, the European Central Bank and the IMF. It has several important payments due this month, including 3.5 billion euros in bond redemptions for securities held by the European Central Bank July 20.

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