According to AltcoinGordon on Twitter, BlackRock spot ETFs purchased 3,960 BTC and 3,220 ETH in a single day, marking a significant inflow into both Bitcoin and Ethereum markets (source: @AltcoinGordon, May 16, 2025). This substantial institutional buying highlights growing confidence among traditional finance giants and suggests potential upward momentum for BTC and ETH prices. Traders should monitor spot ETF flows as a key indicator for crypto market direction, as large acquisitions by BlackRock often precede significant price movements and increased volatility.