A succession of asset bubbles has formed in China, caused by a torrent of speculative money sloshing from stocks to bonds to commodities.

The biggest apparent bubble is in housing, but prices have surged for niche assets, too, such as calligraphy, antiques and art. In May, futures prices for soybean meal, used as pig feed, jumped 40%. The trading volume of 600 million tons was nine times higher than China’s annual consumption. The pipe-making material PVC is up 40% so far this year on the Dalian Commodity Exchange.

The...