China's BYD is set to top Tesla as the world's biggest electric vehicle (EV) seller for the first time. BYD announced that its EV sales grew by nearly 28% last year, reaching more than 2.25 million cars. Tesla, expected to reveal its full 2025 sales soon, reportedly sold about 1.65 million vehicles. Tesla faced challenges including mixed reviews for new models, concerns over Elon Musk's political work, and fierce competition from Chinese rivals. In October, Tesla launched cheaper versions of its two popular US models to increase sales. Elon Musk is under pressure to boost Tesla's sales and stock value to qualify for a massive pay deal worth up to $1 trillion. Part of Musk's deal requires selling a million humanoid robots in ten years, tied to Tesla's work on "Optimus" robots and self-driving "Robotaxis." Tesla's sales dropped early in 2025 after criticism over Musk's role in US President Donald Trump's administration. Musk also runs several other companies like SpaceX, X social media, and the Boring Company, leading some investors to worry about his focus on Tesla. Musk has since promised to cut back his government role. Meanwhile, BYD's sales growth slowed to its lowest rate in five years but it remains a strong player globally. BYD prices often beat rivals, helping it expand rapidly in Latin America, Southeast Asia, and parts of Europe, despite high tariffs on Chinese EVs. In October, BYD said the UK became its biggest market outside China, with sales soaring 880% by September. The star product driving growth there is the plug-in hybrid Seal U SUV.