Lending Club, the peer-to-peer small business lender, is ready to take itself public.

The almost 8-year-old company filed for an initial public offering worth $500 million Wednesday — a placeholder sum that’s used to calculate filing fees. The final sum the company raises could be much higher.

Lending Club had been valued at about $4 billion after a fundraising round earlier this summer.

The company is looking to raise funds amid the growing success of the peer-to-peer lending market, which includes competitors such as Prosper and Upstart. Lending Club has risen to the top of that market and is now the world’s largest online connector of borrowers and investors.

The company has originated over $5 billion in loans as of the end of June. In the six months through June 30, it originated about $1.8 billion of that total, 125% more than over the same period a year earlier, according…