Alchemy announced a $250 million funding round, marking a sevenfold increase in the company's valuation since April. : Start-up Alchemy is benefiting as more companies try to future-proof their businesses by adapting their technologies to the blockchain and through digital collectibles. The San Francisco-based company announced a $250 million funding round on Thursday, boosting its valuation to $3.5 billion. The Series C financing, led by Andreessen Horowitz, marks a sevenfold increase in Alchemy's valuation from April. Alchemy acts as a middleman between blockchain, the technology made famous by bitcoin, and apps that consumers might use on their phones.