In most countries, no one thinks there is a link between a leader’s birthday and the market. That such a theory prevails in China reflects the widespread belief that Beijing’s authoritarian government can produce any economic outcome it wants. Now trust in China’s ability to command and control the economy is faltering. If trust collapses, the global repercussions could be more severe than those from the Greek debt crisis.

When China’s economy slowed following the 2008 global financial crisis, Beijing pumped massive amounts of liquidity into the system. First that money went into the property market, later into the various debt-related products sold through the shadow banking system. But when property slumped and the shadow banks started to pose systemic risks, China had only one major market left to flood—stocks.

Funneling some of China’s $20 trillion in savings into stocks was a last-ditch effort to revive flagging economic growth by giving the country’s debt-laden companies a new source of financing. The aim was to trigger a slow and steady bull run, but the somnolent stock market exploded into one of the biggest bubbles in history.

There are four basic signs of a bubble: prices disconnected from underlying economic fundamentals, high levels of debt for stock purchases, overtrading by retail investors, and exorbitant valuations. The Chinese stock market is at the extreme end on all four metrics, which is rare.