Call that an IPO? By local standards, the debut of Metallurgical Corporation of China was a subdued affair. Not only did the state-owned construction company put on a mere 28 per cent in Shanghai on Monday, about two-fifths this year's average first-day gain, but also the wider market was fractionally up. Sheer force of habit normally compels investors to sell existing holdings to chase the debutant higher.

China bulls have seized on this as evidence of a maturing market, where more rational pricing prevails. That doesn't stack up. At 42 times last year's earnings, MCC was more expensive than the benchmark, at 32. But relative to the stimulus-fuelled industrials sector at 56 times trailing earnings, MCC – which raised $2.8bn – was priced to fly off the shelves.

A more convincing explanation is buyer fatigue. Chinese companies have raised $22bn in IPOs so far this year – more than four times the combined total for the whole of the US and Europe, according to Dealogic data. So far in September, first-day pops have averaged 42 per cent, just over one-third of July's 112 per cent. Openings of new A-share trading accounts by Chinese investors, meanwhile, have fallen for the past six weeks, and are now less than half of the peak volumes of late July. Foreigners have turned tail, too. China equity funds tracked by EPFR saw $477m redeemed last week as investors rotated Asian exposure to India and Korea.