Shares of Contemporary Amperex Technology Co briefly traded at a record premium in the Hong Kong Special Administrative Region over their Chinese mainland-listed peers, as strong earnings and energy supply shocks boosted demand for the battery giant.

CATL’s Hong Kong shares have surged around 35 percent since last week’s earnings beat, pushing their premium over the firm’s Shenzhen-listed stock to a record 46 percent at one point. 

The mainland-listed shares have gained about 16 percent over the same period, driving the gap between the two listings past levels last seen in July, when foreign investor demand in Hong Kong buoyed sentiment.

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The premium has widened even as the city’s broader equity market languished. Morgan Stanley estimates a gap of about 10 percent would be reasonable for CATL, based on the midpoint of premiums for Taiwan Semiconductor Manufacturing Co and BYD Co.

Still, CATL is increasingly viewed as a play on stronger-than-expected fundamentals and the push for energy diversification amid higher oil prices. GigaDevice Semiconductor Inc and China Merchants Bank Co are among a small group of companies in Hong Kong that trade at premiums to their onshore peers, according to data compiled by Bloomberg.