Activity across the cryptocurrency market has been largely subdued on April 15 as traders in the United States have taken an early weekend thanks to the closure of financial markets for the observance of Good Friday. A survey of the top 20 tokens indicates a relatively flat trading day, with Bitcoin (BTC) clinging to support above $40,000. Several lower-ranking altcoins managed to post double-digit gains on the back of recent protocol developments. Top 7 coins with the highest 24-hour price change. Source: Cointelegraph Markets Pro Data from Cointelegraph Markets Pro and TradingView shows that the biggest gainers over the past 24-hours were Quantstamp (QSP), DigitalBits (XDB) and AirSwap (AST). Quantstamp launches NFT Combinator Blockchain security and code audit provider Quantstamp l...