Elon Musk and Bill Gates have continued their war of words over Gates' reported "multi-billion dollar" bet against Tesla as Musk questioned the Microsoft cofounder's defense.
In an interview with French YouTuber HugoDécrypte, Gates defended his record on climate change philanthropy and questioned the benefit of electric vehicles.
"I give a lot more to climate change than Elon or anyone else," Gates said. "I give a lot of philanthropic dollars, I back companies - you know electric cars are about 16% of emissions, so we also need to solve that other 84%."
He added: "But somebody shorting the stock doesn't slow him down or hurt him in any way."
Responding to an extract of the interview on Twitter in which Gates defended his position, Musk simply replied: "Sigh."
Sigh— Elon Musk (@elonmusk) June 4, 2022
Musk said he refused a philanthropic donation from Gates because the Tesla CEO heard he had a $500 million "short", or bet, against the company, which Musk said meant Gates wasn't serious about climate change.
The SpaceX and Tesla boss initially confirmed leaked texts in April showing an exchange between the pair, with Musk since saying the rise in Tesla's share price meant the bet was now worth $2 billion.
The net worth of both has fallen by billions of dollars this year as stock markets slide over fears about rising inflation and interest rates, and the prospect of a recession.
In the interview, Gates also said he hadn't joined Musk', Amazon founder Jeff Bezos' and Virgin Group founder Richard Branson's "space race" because he was more concerned with tackling illnesses such as measles and malaria.