A housing-market bubble is a sustained rise in prices above long-run sustainable or fundamental value, often driven by expectations of further increases. In China, the average price rose from 4,000 to 60,000 yuan per m² and the price-to-income ratio rose from 5.6 to 7.6, reducing affordability for low- and middle-income households. Rising prices may increase wealth and confidence, support construction, bank lending and consumption, but renters do not gain the same wealth. If the bubble bursts after interest rates rise, credit tightens or confidence falls, house prices, consumption, construction and employment may fall, harming lenders and the wider economy. The judgement depends on whether the increase reflects genuine growth and higher incomes or speculation, whether prices are nominal or real, the size of home ownership and the time horizon.