Bitcoin and altcoins are experiencing a tough battle between bulls and bears, with the market trading sideways over the past few days. Profit bookings in the S&P 500 indicate risk appetite, increasing the likelihood of a pullback in Bitcoin and some altcoins. However, the upcoming Bitcoin halving in April is expected to maintain long-term bullish sentiment, with investors likely to view dips as buying opportunities. Key support levels to watch include $50,000 for Bitcoin, $2,717 for Ether, and $368 for BNB.