On Friday, the Palo Alto firm announced that it is boosting its latest stock offering by $140 million, on top of the $500 million in new equity the firm planned to issue, according to a report in the Wall Street Journal.

And the offering could balloon to as much as $750 million if the firm’s underwriters exercise their options to purchase shares.

The new offering comes on top of $4 billion Tesla has raised since 2013. According to the Journal the new round of fundraising “suggests the cost of disrupting the global auto industry with its pricey electric vehicles is more expensive than Chief Executive Elon Musk initially thought.”

Tesla says it will sell fewer than 55,000 cars this year.