CEX.IO's educational arm CryptoComLearn has released a comprehensive guide on position sizing, a discipline that helps traders cap per-trade losses and avoid emotional decisions. The article moves from risk tolerance to the exact formula, then addresses the overlooked risk of price gaps.
What Position Sizing Is — and Why It Matters
Position sizing measures the exact amount of capital or units committed to a single trade. Most traders use high leverage and suffer wild portfolio swings; proper sizing smooths those swings. The core ingredients are your account equity, the risk percentage you assign to one trade, the stop-loss distance, and the number of units (lots, dollars, pips, or shares) in the position.
Account Risk: The 1-2% Rule
Professional traders rarely risk more than 1% to 2% of their equity on any single trade. For active intraday traders, 1% is preferable; swing or trend traders can use 2%. Example: a $10,000 account with a 2% limit means no more than $200 loss per trade. Even a 10-loss streak would leave 80% of the original capital intact.
Trade Risk and Stop-Loss Positioning
Once the account risk is set, the trader adjusts the stop-loss for a specific trade. Using a BTC/USDT buy at $37,000 with a stop at $36,000, the price difference is $1,000. To keep the loss under 2% ($200), the position size must be calculated accordingly. Leveraged trades require further adjustment; traders can reduce the number of units to allow a wider stop while staying under the risk cap.
The Formula: Three Steps to Find the Right Size
The guide provides a clear formula: [(Account Size × Risk %) / (Entry Price − Stop Loss)] × Entry Price. Using the BTC/USD example: ($10,000 × 2%) / ($37,000 − $36,000) × $37,000 = 0.2 BTC. This ensures that a drop to $36,000 triggers exactly a $200 loss, matching the predefined risk.
Price Gap Risk — When Stops Slip
Markets can gap due to FOMC speeches, earnings, interest rate decisions, or sudden order imbalances. If the price jumps past your stop, the loss may exceed the 2% limit. The article advises either cutting the risk in half (to 1%) or simply skipping the trade until the event passes.
The guide concludes that cold, logic-based sizing removes emotion and prevents outsized losses. It is for educational purposes only and does not constitute investment or financial advice; digital assets involve risk and readers should do their own research.