(Yicai) Feb. 10 -- Shares in Black Sesame Technologies plunged by as much as 51 percent today after the Chinese autonomous driving chipmaker explained today that it is a long-term and regular supplier to leading carmakers, such as BYD, but did not mention any connection to BYD’s new self-driving system.

Black Sesame’s share price [HKG:2533] closed down 39.5 percent at HKD23.45 (USD3). Earlier in the day it sank to HKD19.

The stock had gained almost 70 percent in value from Feb. 6 to Feb. 7, adding over HKD7.5 billion (USD963 million) to the Wuhan-based company’s market capitalization, on expectations that Black Sesame would be supplying chips to BYD’s new electric car models, which will be equipped with the ‘God’s Eye’ self-driving system. The launch is expected to be announced tonight.

BYD does use Black Sesame’s chips and these chips are already in mass production, Black Sesame said on Feb. 7, without going into further details.

BYD's intelligent driving technology is primarily self-developed and the main supplier is BYD Electronics, company insiders told Yicai. But the Shenzhen-based firm does have a long-term partnership with Black Sesame, they added.

Black Sesame is a secondary System-on-a-Chip producer in the midstream of the autonomous driving value chain. It provides autonomous driving products and solutions in the form of SoC-based bundled- and algorithm-based solutions.

Black Sesame was the world's third-largest supplier of high-performance automotive-grade SoCs in 2022 based on shipment volume, according to US market research firm Frost & Sullivan.

Editor: Kim Taylor