The latest crypto market recap for September 21, 2026 shows broad strength in major assets, a short squeeze, aggressive altcoin rotation, and sharp volatility in low-liquidity tokens. Bitcoin and Ethereum extended their gains as renewed exchange-traded fund demand supported the broader market. U.S. spot Bitcoin ETFs recorded $433.03 million in net inflows on 18 September, while Ethereum ETFs attracted $143.8 million and Solana products received $47.62 million.