Tesla CEO Elon Musk said the compensation he received last year was ’net negative’ as he had paid for most of his company-related expenses, responding to a Twitter user’s comments on Wednesday.

Musk was awarded over US$517 million last year, topping Bloomberg’s Pay Index, which tracks the highest paid executives in the U.S.

In a follow-up tweet, Musk said there was a campaign of being pushed by those betting against Tesla to sow "fear, uncertainty and doubt."