Affiniti, a fintech startup focused on providing expense management solutions for small and medium-sized businesses (SMBs), has raised $17 million in a Series A funding round led by SignalFire. The company, founded by 20-year-old Aaron Bai and 22-year-old Sahil Phadnis, aims to offer SMBs customizable credit cards and software for managing expenses, similar to services provided by Brex and Ramp. This comes just six months after the startup raised an $11 million seed round. The startup plans to use the new funds to expand its offerings, including banking, bill pay, cash flow analytics, and integrations with enterprise resource planning and point-of-sale applications. Affiniti has already grown to serve 1,800 customers and processes about $20 million in monthly transaction volume. In a separate development, LMArena, a startup spun off from UC Berkeley's Chatbot Arena project, has secured $100 million in seed funding. The round was co-led by Andreessen Horowitz and UC Investments, valuing the company at $600 million. LMArena focuses on developing AI reliability through scientific rigor and aims to build infrastructure for open, reliable AI evaluation. Catena Labs, another startup in the AI and finance space, has raised $18 million to launch an 'AI-native bank.' The funding round was led by a16zcrypto, with participation from Breyer Capital, Circle Ventures, and CB Ventures. Catena Labs is working on financial infrastructure tailored for AI agents and their human collaborators. The startup was co-founded by Sean Neville, who is also a co-founder of Circle. Datacurve AI, a Y Combinator W24 company, has raised $14 million in a Series A round at a $150 million valuation, led by Chemistry Fund. The startup, which provides premium curated coding data for applications and large language models, has achieved an annual recurring revenue of approximately $9 million in just 13 months.