Emerging-market stocks fell the most in two years and currencies tumbled on concern Greece’s rejection of austerity will spur its exit from the euro area, damping demand for riskier assets.

The MSCI Emerging Markets Index lost 2.5 percent to 940.52 at 1:35 p.m. in Hong Kong, wiping out this year’s advance. A gauge of Hong Kong-traded Chinese companies plunged 5 percent and South Korean shares headed for the steepest loss since 2012. Malaysian stocks sank 1.3 percent as the ringgit slid to the weakest level since a dollar peg was scrapped in 2005. Currencies in Hungary, Poland and Romania fell at least 0.6 percent against the dollar. Turkey’s lira weakened 0.5 percent.

Sixty-one percent of voters backed Greek Prime Minister Alexis Tsipras’s rejection of further spending cuts and tax increases in an unprecedented referendum that’s also taken the country to the brink of financial collapse. German Chancellor Angela Merkel and French President Francois Hollande called for an emergency leaders’ summit on Tuesday.

“Today’s move will be mostly driven by fund flows in reaction to Greece,” Alan Richardson, a Hong Kong-based money manager at Samsung Asset Management Ltd., which oversees about $112 billion, said via e-mail. “Global macro factors are highly volatile and unpredictable because outcomes depend on politics and human emotions.”

Stock Valuations

The developing-nation index has declined 1.8 percent this year and trades at 11.4 times projected 12-month earnings, data compiled by Bloomberg show. The MSCI World Index has risen 1.7 percent in 2015 and is valued at a multiple of 16.1.

The Hang Seng China Enterprises Index headed for the biggest slump since November 2011. The Shanghai Composite Index climbed 0.6 percent, erasing earlier gains of as much as 7.8 percent. Over the weekend, China suspended initial public offerings, while brokerages pledged to buy shares and the central bank said it would provide liquidity for margin trading.

All 10 industry groups in MSCI’s developing-nation measure dropped, led by industrial and technology companies. CRRC Corp Ltd. tumbled 9.9 percent in Hong Kong, while Tencent Holdings Ltd. slumped 9.5 percent.

South Korea’s Kospi index sank 2.3 percent. The FTSE Bursa Malaysia KLCI Index headed for the steepest loss since April 30 and the ringgit dropped 0.7 percent. A Malaysian task force is investigating a money trail that allegedly showed funds ending up in Prime Minister Najib Razak’s bank accounts, a claim he says is political sabotage, while some cabinet members voiced support.