According to Crypto Rover (@rovercrc), altcoins are experiencing significant sell-offs, with several major tokens seeing double-digit percentage losses in the past 24 hours (source: Crypto Rover on Twitter, June 18, 2025). The sharp altcoin decline is attributed to a combination of Bitcoin (BTC) dominance surging, regulatory uncertainty in the US and Asia, and large-scale liquidations by leveraged traders (source: CoinGlass, June 18, 2025). Traders should monitor BTC price action and macroeconomic factors closely, as further volatility is expected in the altcoin market. Risk management and stop-loss strategies are critical in this environment.