The more practical framing concerns dosage and implementation: how much bitcoin a balanced portfolio can carry and under what rule it should be held. Starting from a conventional 60/40 portfolio of global equities and core bonds, we introduced spot bitcoin at 2.5% and 10% weights with monthly rebalancing across January 2021 to March 2026. Higher weights also brought more volatility and deeper maximum drawdown, and that trade sits at the heart of the sizing question. We then repeated the exercise with a rules-based trend sleeve in place of spot bitcoin, one that toggles between bitcoin and cash on trend signals. This is the same logic behind systematic tools like the CoinDesk Bitcoin Trend Indicator, which signals the direction and strength of bitcoin momentum from CoinDesk Data.