Kalshi, a prediction market platform, recently raised over $300M at a $5B valuation and has since grown 3x, hitting $50B in annualized volume. With backing from Sequoia, a16z, Paradigm, and Coinbase, and its recent expansion to 140+ countries, the original poster suggests its $5B valuation is "undervalued af" based on raw metrics. This implies potential for significant future growth and a higher valuation for the private company.