China’s home prices may slump 30% as local authorities implement government measures to crack down on property speculation, according to brokerages including China Jianyin Investment Securities.

Home sales plunged nearly 40% by both units and floor space in 15 major cities last week, extending a streak of declines since mid-April, according to Zheshang Securities. China on May 2 raised banks’ reserve requirements for the third time this year, adding to last month’s down-payment and interest rate increases on second mortgages.

The government is escalating efforts to avert asset bubbles after a record surge in property prices. Beijing has gone further, limiting residents in the capital to buying one new home starting this month, the first city to implement a restriction authorized by the central government.