Why Position Sizing Is Not Optional
You can have the best strategy in the world — perfect entries, precise exits, a 70% win rate — and still blow a prop trading evaluation if your position sizing is wrong. This is not a theoretical risk. It is the most common reason traders fail at Dolvero and every other prop firm. They know what to trade and when to trade it, but they size their positions based on gut feeling rather than mathematics, and one adverse move takes them past the drawdown limit.
Position sizing is the translation layer between your strategy and your account's risk rules. At Dolvero, those rules are clear: maximum 2% risk per trade, 5% maximum daily loss, and 10% static drawdown. Every position you open must be sized so that your stop loss — if hit — costs no more than 2% of your account balance. This article will show you exactly how to calculate that for the two most popular account sizes: $50,000 and $100,000.
The Core Formula
Position sizing in trading comes down to one formula:
Lot Size = (Account Balance × Risk Percentage) / (Stop Loss in Pips × Pip Value per Lot)
Let us break down each component:
- Account Balance: Your current account value. On a fresh $50K account, this is $50,000. On a $100K account, $100,000.
- Risk Percentage: The maximum you are willing to lose on this trade. At Dolvero, the hard cap is 2%, but many professional traders use 1% or even 0.5% as their default.
- Stop Loss in Pips: The distance between your entry price and your stop loss, measured in pips.
- Pip Value per Lot: The dollar value of one pip movement per standard lot. This varies by instrument.
Position Sizing on a $50,000 Account
Maximum dollar risk per trade
At 2% risk (the Dolvero maximum): $50,000 × 0.02 = $1,000 per trade
At 1% risk (recommended for most traders): $50,000 × 0.01 = $500 per trade
At 0.5% risk (conservative approach): $50,000 × 0.005 = $250 per trade
Forex examples — $50K account at 1% risk ($500)
For major forex pairs where the quote currency is USD (EUR/USD, GBP/USD, AUD/USD), one pip on a standard lot equals $10. Here are the lot sizes for common stop loss distances:
- 15-pip stop loss: $500 / (15 × $10) = 3.33 lots
- 25-pip stop loss: $500 / (25 × $10) = 2.00 lots
- 40-pip stop loss: $500 / (40 × $10) = 1.25 lots
- 60-pip stop loss: $500 / (60 × $10) = 0.83 lots
- 100-pip stop loss: $500 / (100 × $10) = 0.50 lots
For USD/JPY and other pairs where USD is the base currency, pip values differ slightly depending on the current exchange rate. As a general rule, at USD/JPY around 150.00, one pip per standard lot is approximately $6.67. Adjust your lot sizes accordingly:
- 20-pip stop on USD/JPY: $500 / (20 × $6.67) = 3.75 lots
- 50-pip stop on USD/JPY: $500 / (50 × $6.67) = 1.50 lots
Gold (XAU/USD) — $50K account at 1% risk ($500)
Gold has a pip value of $10 per standard lot per 1-point move (one pip = $0.10 move in gold = $10 per lot). Typical stop loss distances on gold are wider than forex:
- $5.00 stop (50 pips): $500 / (50 × $10) = 1.00 lot
- $10.00 stop (100 pips): $500 / (100 × $10) = 0.50 lots
- $20.00 stop (200 pips): $500 / (200 × $10) = 0.25 lots
Indices (US30, NAS100) — $50K account at 1% risk ($500)
Index CFDs vary significantly in pip value and contract specifications across brokers. On a typical MT5 setup:
- US30 (Dow Jones): If 1 point = $1 per lot, a 50-point stop = $500 / $50 = 10 lots. Always verify the contract specification in MT5 before placing a trade.
- NAS100 (Nasdaq): Contract specs vary. Check the "Contract Size" field in MT5 Symbol Properties. Calculate from there.
The critical rule: always check the contract specification in MT5 for any instrument before calculating your lot size. Assumptions about pip values kill accounts. You can verify all instrument specifications within your MT5 terminal after starting your evaluation at app.dolvero.com/start. For full details on account sizes and fees, visit Pricing.
Position Sizing on a $100,000 Account
Maximum dollar risk per trade
At 2% risk: $100,000 × 0.02 = $2,000 per trade
At 1% risk: $100,000 × 0.01 = $1,000 per trade
At 0.5% risk: $100,000 × 0.005 = $500 per trade
Forex examples — $100K account at 1% risk ($1,000)
- 15-pip stop loss: $1,000 / (15 × $10) = 6.67 lots
- 25-pip stop loss: $1,000 / (25 × $10) = 4.00 lots
- 40-pip stop loss: $1,000 / (40 × $10) = 2.50 lots
- 60-pip stop loss: $1,000 / (60 × $10) = 1.67 lots
- 100-pip stop loss: $1,000 / (100 × $10) = 1.00 lot
Notice the pattern: a $100K account allows exactly double the lot size of a $50K account for the same stop loss distance and risk percentage. The math is linear and scalable.
Gold (XAU/USD) — $100K account at 1% risk ($1,000)
- $5.00 stop (50 pips): $1,000 / (50 × $10) = 2.00 lots
- $10.00 stop (100 pips): $1,000 / (100 × $10) = 1.00 lot
- $20.00 stop (200 pips): $1,000 / (200 × $10) = 0.50 lots
The Daily Loss Limit Constraint
Position sizing does not exist in isolation. Even if every individual trade is sized at 2% risk, you must also consider the 5% daily loss limit. On a $50K account, that is $2,500 per day. On a $100K account, $5,000 per day.
This means:
- At 2% risk per trade, you can sustain a maximum of two full losing trades before you are close to the daily limit on a $50K account (2 × $1,000 = $2,000, leaving only $500 of buffer).
- At 1% risk per trade, you can sustain four full losing trades before approaching the daily limit on a $50K account (4 × $500 = $2,000).
- On a $100K account at 1% risk, you get the same four-trade buffer — 4 × $1,000 = $4,000 against a $5,000 daily limit.
This is why professional traders rarely use the full 2% allocation. Trading at 1% risk per trade gives you meaningful room to absorb losing streaks within a single day without breaching the daily loss limit. For details on all risk parameters, see the Dolvero Rules.
Multiple Open Positions: Correlation Risk
One of the most dangerous position sizing mistakes is ignoring correlation. If you are long EUR/USD and long GBP/USD simultaneously, each at 1% risk, your effective risk is not 2% — it is closer to 1.7-1.9% because EUR/USD and GBP/USD are highly correlated. Both trades will likely win or lose together.
Similarly, being long gold and short USD/JPY is a correlated bet on USD weakness. Three correlated trades at 1% risk each can easily result in a 3% loss if the correlation fires against you — and that puts you dangerously close to the daily loss limit.
The rule of thumb: treat correlated positions as a single risk unit. If you have two highly correlated trades open, size each at 0.5% rather than 1%. Your total correlated exposure should never exceed 2% of your account.
Adapting Size During the Evaluation
Your position sizing should not be static throughout the evaluation. It should adapt based on your current drawdown and progress toward the target. Here is a practical framework:
When you are ahead of target
If you are up 6% in Phase 1 (target is 10%), you have a buffer. You can maintain your standard 1% risk per trade. The static drawdown model means your floor has not moved — on a $50K account, it is still $45,000, and you are at $53,000. You have $8,000 of room. There is no reason to increase risk just because you are winning.
When you are in drawdown
If you are down 4% from your starting balance, the math changes. On a $50K account, you are at $48,000 with a floor of $45,000 — that is $3,000 of remaining room, or 6% of your current balance. Reduce your risk per trade to 0.5% or lower. At $48,000 and 0.5% risk, your maximum loss per trade is $240. That gives you over twelve losing trades before the floor, which is a much more comfortable margin.
The first week calibration
On a new evaluation account, your first five trades should be at 0.5% risk or less. You are calibrating to the platform, the spreads, the execution speed, and the psychological weight of the account size. Even experienced traders feel different on a $100K account versus their usual $10K demo. Give yourself permission to start small. The evaluation has no time limit — use that to your advantage.
Common Position Sizing Mistakes
- Rounding up lot sizes: The calculation says 2.37 lots, but you enter 3.00 because it is a "round number." That 27% increase in position size can be the difference between a 1.5% loss and a 2% loss on a bad trade. Always round down.
- Ignoring spread cost: Your stop loss is 15 pips, but the spread is 2 pips. Your effective stop is 17 pips. Size for 17, not 15.
- Using the same lot size for every instrument: 1.00 lots on EUR/USD is not the same risk as 1.00 lots on GBP/JPY or XAU/USD. Each instrument has a different pip value. Calculate individually.
- Not adjusting for account growth or decline: If your $50K account is now at $54,000, your 1% risk is $540, not $500. If it has declined to $47,000, your 1% risk is $470, not $500. Use current balance, not starting balance.
- Sizing before finding the stop: The correct sequence is: (1) identify the trade, (2) determine the stop loss level based on market structure, (3) calculate the lot size from the stop loss distance. Never decide the lot size first and then find a stop loss that fits — that is backwards.
Building a Position Sizing Spreadsheet
Every serious trader should have a position sizing calculator. It does not need to be complex. A simple spreadsheet with four inputs — account balance, risk percentage, stop loss in pips, and pip value — will calculate your lot size instantly. Use it before every single trade. No exceptions.
MT5 also has built-in trade calculators and third-party position sizing EAs (Expert Advisors) that can automate this process. There is no excuse for guessing your lot size. The math takes ten seconds, and those ten seconds can save your account.
Putting It All Together
Position sizing is not glamorous. It does not generate alpha. It does not find entries or predict market direction. But it is the mechanism that keeps you in the game long enough for your strategy to work. At Dolvero, the rules are clear and the drawdown model is fair — your job is to size every position so that no single trade, no single day, and no single week can end your evaluation.
Start with 0.5-1% risk per trade. Check your daily exposure against the 5% limit. Account for correlation between positions. Adjust size based on your drawdown status. And always, always calculate before you click.
Ready to apply disciplined position sizing to a real evaluation? Visit app.dolvero.com/start to choose your account size, read the full risk parameters at Rules, and explore How It Works for the complete evaluation process. Stay informed about rule updates via the Changelog. Every payout made to funded traders is publicly visible on the Live Ledger — proof that disciplined sizing leads to real results.
