Crowdfunding giant Lending Club, which filed for a $1-billion IPO late last year, is nearly doubling its office footprint in downtown San Francisco. The peer-to-peer lending firm is leasing 120,000 square feet in the Financial District at 595 Market Street. The move follows Uber’s 173,000-square-foot lease at 555 Market earlier this year. Lending Club was represented by Avison Young in the move.