Emerging-market stocks headed for a three-month low and currencies weakened on concern Greece's rejection of austerity will spur its exit from the eurozone, damping demand for riskier assets.
The MSCI Emerging Markets Index lost 2.1 percent to 943.94 in morning trade in London. Hong Kong's Hang Seng China Enterprises Index sank 3 percent. The Shanghai Composite Index rose 2.4 percent amid efforts by the government to shore up equities. South Korean stocks lost 2.4 percent. Malaysia's ringgit slid to the weakest level since a dollar peg was scrapped in 2005. Currencies in Russia, Hungary and Poland fell at least 0.6 percent versus the dollar.
Sixty-one percent of voters backed Greek Prime Minister Alexis Tsipras's rejection of further spending cuts and tax increases in a referendum that has also taken the country to the brink of financial collapse.
Alan Richardson, a Hong Kong-based money manager at Samsung Asset Management Ltd, said: "Global macro factors are highly volatile and unpredictable because outcomes depend on politics and human emotions."
The developing-nation index has declined 1.3 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 so far this year and is valued at a multiple of 16.1.
The Hang Seng China Enterprises sank to a three-month low. Most of the equities dropped in Shanghai as a fresh round of government support measures failed to spark gains outside the largest State-owned enterprises.
A Bloomberg gauge tracking 20 developing-nation currencies fell 0.2 percent, its second day of declines. The rouble headed for a one-month low and the Micex Index lost 0.5 percent. Brent crude slid below $60 per barrel for the first time since April.
Egypt's stock gauge dropped 2.9 percent, poised for the lowest close since June 2014, while South African equities decreased 1.3 percent. Polish shares declined 1 percent.