Fomo, a social crypto trading platform that lets users execute on-chain trades across multiple blockchains from a single mobile app — without managing wallets, bridges, or gas fees — announced on Monday a $75 million Series B at a $550 million valuation, led by Index Ventures with participation from Union Square Ventures and returning investor Benchmark. The raise, which brings the New York-based startup’s total disclosed funding to roughly $94 million, arrived twelve weeks after the Securities and Exchange Commission and Commodity Futures Trading Commission jointly clarified that non-custodial wallet interfaces do not need to register as broker-dealers — a regulatory ruling that validated precisely the architecture Fomo’s…