Charles Schwab's latest research indicates that cryptocurrencies like Bitcoin (BTC) and Ethereum (ETH) exhibit high volatility, which can significantly increase overall portfolio volatility even with a small allocation of 1% to 3%. The report notes that both BTC and ETH have historically experienced drawdowns exceeding 70%, suggesting there is no universal "correct allocation" and that it should depend on an investor's risk tolerance and capacity for loss. Schwab emphasizes that crypto assets are better suited as high-risk satellite positions rather than core holdings.