The ChiNext has only closed lower once following the 2015 peak. On September 15, 2015, it fell to 1797.56, but that was a spike down that was reversed the next day. Today's close at 1830.85 is the second lowest closing price. The intraday low was a new post-peak low of 1783.74.
This article about today's dip caught my eye.
Barron's: ChiNext Tumbles 3.7% As China’s Investors Ditch Growth For Value
Chinese retail investors, who typically prefer growth stocks, have discovered a new concept – value – as they chase after blue-chip Old Economy stocks over New Economy favorites, playing on President Xi Jinping’s supply-side reform.This is exactly the same trend underway in the American stock market. Here's the price-ratio of ChiNext vs the Shanghai Composite, and the price-ratio of S&P 500 Growth vs Value in blue.