Position Sizing & Portfolio Allocation

Position sizing is the most important risk management tool available to you. It answers the question: "How much of my portfolio should I allocate to any single investment?" Getting position sizing right can be the difference between surviving a bear market and being wiped out.

The Cardinal Rule: Never Risk More Than You Can Afford to Lose

This is not just a cliché — it is the foundation of risk management. Before investing a single rupee in crypto, you should have an emergency fund covering 3-6 months of expenses, no high-interest debt, and money you will not need for at least 3-5 years. In Sri Lanka, where the 2022 crisis showed how quickly financial stability can erode, this buffer is especially critical.

The Percentage-of-Portfolio Approach

A disciplined approach to position sizing involves setting maximum allocation limits:

Asset Type	Suggested Max Allocation	Risk Level
Bitcoin (BTC)	50-70% of crypto portfolio	Lower (for crypto)
Ethereum (ETH)	15-30%	Moderate
Large-cap alts	5-15%	Higher
Small-cap alts / DeFi	0-5%	Very high

The 1-2% Rule

Professional traders often follow the 1-2% rule: never risk more than 1-2% of your total portfolio on a single trade. This means that if a trade goes completely wrong, you lose at most 2% of your portfolio. At that rate, you would need to lose 50 consecutive trades to be wiped out — which is essentially impossible if your strategy has any edge at all.

For example, if your total crypto portfolio is LKR 500,000, the maximum you should risk on any single trade is LKR 5,000-10,000 (1-2%). This does not mean your position size is only LKR 10,000 — it means the amount you are willing to lose (the distance to your stop-loss) should not exceed that amount.

Dollar-Cost Averaging (DCA)

For long-term investors, dollar-cost averaging is a powerful position-sizing strategy. Instead of investing a lump sum all at once, you invest a fixed amount at regular intervals — regardless of price. This smooths out volatility and removes the emotional temptation of trying to time the market.

A Sri Lankan investor might commit to buying LKR 5,000 of Bitcoin every week or every month. When prices are high, they buy less Bitcoin; when prices are low, they buy more. Over time, this results in a lower average cost than most people achieve by trying to time their entries.

Rebalancing

As prices change, your portfolio allocation drifts. If Bitcoin doubles while your altcoins stay flat, your BTC allocation might grow from 60% to 75%. Periodic rebalancing — selling some of what has grown and buying more of what has shrunk — helps maintain your target allocation and systematically takes profits from winners.