What's behind China's stock market plunge

After a 30% surge that made the Shanghai Composite Index the best-performing major stock exchange in the world, China's onshore market has stalled out since April.

Details: First, it was a change of tone from the Communist Party's top decision-making body signaling a tougher stance on economic stimulus.

• The central bank also stopped injecting money into the financial system for 18 consecutive days in April.
• Then the country's top companies failed to impress during earnings season.

Where it stands: That pushed Chinese stocks down almost 6% from their April high. Monday's market rout brought losses on the index to 11% from the high, technically marking the start of a correction, according to the South China Morning Post.

• The sell-off hit both China's onshore and offshore markets, SCMP reports. "Out of the 3,524 companies that traded on the Shanghai and Shenzhen exchanges on Monday, 3,417 fell and the remaining 107 rose, while all the 50 constituents on the Hang Seng Index dropped."

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