According to @rovercrc, altcoins are "breaking out now," flagging a live momentum shift that could open short-term breakout setups in ALTs if confirmed by market-wide strength (source: Crypto Rover on X, Sep 21, 2025). Traders can seek confirmation via 1H closes above recent ranges on the total altcoin market cap index (TOTAL3) alongside rising volume, and by monitoring strength on key relative pairs like ETH/BTC and SOL/BTC for breadth follow-through (source: Crypto Rover on X, Sep 21, 2025). Risk management remains critical: if momentum stalls or BTC dominance (BTC.D) turns higher, altcoin upside can fade, so consider using prior breakout lows as invalidation and trim into nearby resistance (source: Crypto Rover on X, Sep 21, 2025).