Stablecoins have emerged as a significant profit engine in the cryptocurrency market, with Tether (USDT) and Circle (USDC) capturing 85% of the global market share. Tether, backed by $100 billion in reserves, reported a staggering net profit of $13.7 billion for 2024, achieving a 99% profit margin. The company's valuation has now reached an estimated $50 billion, putting it on par with major tech firms like OpenAI and SpaceX. In addition to Tether's success, decentralized finance (DeFi) protocols such as MakerDAO, Frax, and Aave are capitalizing on stablecoin models to generate revenue through interest income and token economics. Despite these lucrative opportunities, the sector faces challenges including asset volatility, opaque revenue distribution, and regulatory risks.