Contemporary Amperex Technology Co has once again overtaken oil giant PetroChina Co in market value, as investors pile into the battery maker on war-driven optimism over green energy.

CATL’s Shenzhen-listed shares climbed as much as 6.7 percent Thursday on better-than-expected quarterly profit and a plan to expand in critical minerals. Its Hong Kong stock jumped as much as 11 percent. That pushed its market cap to a record high of 2.1 trillion yuan ($306 billion).

The results provided a fresh tailwind for the stock, which had been climbing since the Middle East conflict broke out. CATL’s energy storage business has gained attention as investors seek exposure to companies seen as helping reduce dependence on fossil fuels.

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The strong numbers reported by CATL confirm the “storage boom” as well as the company’s advantage in controlling costs due to its business scale and efficiency, Bloomberg Intelligence analysts Joanna Chen and Jason Zhao wrote in a note.

CATL now ranks as China’s third-largest onshore stock, behind the nation’s two biggest state-owned banks.

After trading places several times toward the end of last year, PetroChina gained a big lead over CATL in market value as oil spiked on the start of the Iran war. China’s largest oil and gas producer has fallen back as crude pared gains on recent ceasefire talks, and after regulators signaled they would limit fuel price hikes to cushion the impact on consumers.