The Core Concept of Rebalancing
Imagine you start with a target allocation: 50% Bitcoin, 25% Ethereum, and 25% USDC (Stablecoins). Over a blistering 3-month bull market, Bitcoin doubles in price. Your actual portfolio now is severely skewed, perhaps sitting at 70% Bitcoin, 20% ETH, and 10% USDC.
Rebalancing is the act of mathematically forcing your portfolio back to its original target weights. In this scenario, you must sell off a massive chunk of your overweight, skyrocketing Bitcoin, and use those profits to buy more of the underperforming ETH and flat USDC.
Automating "Buy Low, Sell High"
Human psychology is horribly suited for trading. When an asset pumps 100%, your brain screams "buy more!" When it crashes 50%, terror tells you to "sell it all!"
By adhering to a strict rebalancing schedule, the math forces you to do the exact opposite. If an altcoin crashes hard, its allocation weight drops below your target, systematically forcing you to deploy your stablecoins to "buy the bloody dip." If a coin moons, it exceeds its limit, forcing you to algorithmically lock in profits at the top.
Threshold Rebalancing vs. Time Rebalancing
There are two main methods. "Time-based Rebalancing" means you adjust the portfolio rigidly at the end of every quarter or month, regardless of market action. It is great for passive, long-term investors.
"Threshold Rebalancing" means you only adjust when an asset deviates by a specific percentage (e.g., if Bitcoin strays +/- 10% from its target weight). Due to the violent volatility of crypto, Threshold rebalancing is heavily preferred by professionals, as it captures the massive intraday wings that a calendar method would completely miss.