1. Robinhood: Robinhood is a commission-free stock trading platform that has gained significant traction among investors, especially millennials.

2. Stripe: Stripe is a payments platform that allows businesses to accept and manage online payments easily. It has gained popularity for its user-friendly interface and developer-friendly APIs.

3. Plaid: Plaid is a fintech company that enables users to securely connect their bank accounts to various apps and platforms such as Venmo, Coinbase, and Robinhood. Its integration capabilities have made it a go-to for many fintech startups.

4. Klarna: Klarna is a Swedish fintech company that offers buy-now-pay-later services to online shoppers. It has gained popularity for its seamless checkout process and flexible payment options.

5. SoFi: SoFi (Social Finance Inc.) is an online personal finance company that provides student loan refinancing, personal loans, mortgage loans, and wealth management services.

6. Chime: Chime is an online banking platform that offers no-fee banking services and aims to disrupt traditional banking models by providing a mobile-first approach and innovative features like early paycheck access.

7. Revolut: Revolut is a digital banking and financial services platform that offers currency exchange, budgeting tools, cryptocurrencies, and even stock trading.

8. OnDeck: OnDeck is an online small business lender that uses technology to provide fast and convenient access to capital for small businesses.

9. Lemonade: Lemonade is an insurtech startup that offers homeowners and renters insurance through its innovative mobile app, leveraging artificial intelligence and automation to simplify the insurance process.

10. Wealthfront: Wealthfront is a robo-advisor that uses algorithms and automation to provide investment management services at a fraction of the cost of traditional wealth management firms.