SoftBank Vision Fund is injecting $800 million into UK fintech Greensill, according to a person familiar with the matter.

The investment values Greensill, which provides alternative supply chain funding to companies, at $3.5 billion, the person said.

That’s more than double the level of almost a year ago, when the firm received $250 million from General Atlantic LLC. Greensill declined to comment, while SoftBank couldn’t immediately be reached for comment.

Greensill estimates the largely untapped market for working capital finance at $55 trillion. The money from Vision Fund will help it accelerate its expansion and develop new technologies to make more capital accessible to its clients, the person said.

It will also speed up its recent entry into Brazil as it advances plans to enter other markets, including China and India.

Greensill, co-founded in 2011 by ex-Morgan Stanley banker Lex Greensill, is taking on traditional banks, which typically offer working capital finance to a limited number of large clients. Since 2015, the company has delivered annual growth of more than 100%.

The bulk of the Vision Fund is was initially backed primarily from the Saudi Arabian government as well as capital from Apple Inc and the government of Abu Dhabi.