An overhaul of listing and trading rules has driven a 16-year-old board for start-ups on the Shenzhen Stock Exchange to an all-time high, and traders believe the listed companies’ above-average earnings growth and exposure to renewable energy will extend the record-setting run.

The ChiNext 50 Index of the board’s 50 biggest stocks and the ChiNext Composite Index both broke highs set in 2015 this week, outpacing other equity gauges of yuan-denominated stocks, which have yet to fully recoup their losses since the beginning of the Middle East conflict.

Buying sentiment on ChiNext companies ignited after the China Securities Regulatory Commission unveiled a package of reforms earlier this month, allowing pre-profit tech companies to list and introducing market makers to boost secondary-market trading and liquidity. The market regulator’s changes marked the most sweeping reforms for the board, bringing it up to par with the Nasdaq-style Star Market on the Shanghai bourse.

“This reform is expected to boost the risk appetite for innovative growth companies,” said Xu Chi, an analyst at Zhongtai Securities. “But the broader implications of this could be a valuation repair [or re-rating] of growth stocks of higher quality.”

The ChiNext board, which opened with 28 companies in October 2009, now hosts 1,396 listings with a combined market value of 20.3 trillion yuan (US$2.97 trillion), according to the Shenzhen exchange. That accounts for 42 per cent of the total capitalisation of the Shenzhen bourse, the second largest on the mainland.

The biggest stock on the board is Contemporary Amperex Technology Ltd (CATL), the world’s biggest maker of lithium batteries for electric vehicles, which is capitalised at 2.02 trillion yuan. Zhongji Innolight and Eoptolink Technology, both involved in the artificial intelligence data centre supply chain, are ranked second and third. The three represented 46 per cent of the weighting of the ChiNext 50 Index, according to Bloomberg data.

The ChiNext gauge has risen 18 per cent this year, beating the 3.4 per cent gain in China’s benchmark CSI 300 Index and the 6.6 per cent advance in the gauge tracking the technology-heavy Star Market. Shares of CATL have climbed 20 per cent since the start of the year.