MetaTrader EAs and Position Sizing: The Missing Piece

It’s 10:30 PM, and you’re watching a trade setup that’s been developing for the last three hours. The technicals align — a clean breakout on the daily, momentum picking up, and your strategy’s entry trigger just fired. You open MetaTrader, ready to execute. But then you pause. That moment of hesitation isn’t about the direction of the trade; it’s about the size. You know you should risk 1% of your account, but your stop-loss distance is 50 pips, and you’re trading gold on a USD account. The calculation isn’t complicated, but it’s easy to get wrong under pressure. So you reach for a calculator, second-guess the lot size, and either enter too large (and sweat through the night) or too small (and watch the trade succeed while you barely make a dent in your P&L).

This is the trader’s dilemma that MetaTrader’s built-in tools don’t solve. Despite being the industry-standard platform for retail and professional traders alike, MT4 and MT5 ship without a native position sizer. The formula isn’t difficult: Risk Amount = Account Balance × Risk %, and Lot Size = Risk Amount ÷ (Stop Loss Pips × Pip Value). But doing this manually for every trade — while the market moves — introduces friction, and friction breeds errors.

That’s where the Position Sizer Expert Advisor comes into the picture. Designed by EarnForex, this free EA for both MT4 and MT5 automatically calculates the optimal lot size based on your risk tolerance, account currency, stop-loss distance, commission structure, and instrument specifications. It’s a feature-rich tool that handles everything from margin requirements to portfolio risk, with an interface that updates in real time as price moves.

To get it running, you download the EA from the EarnForex GitHub repository, copy it into your MetaTrader data folder (MQL4 or MQL5/Experts), compile the code in MetaQuotes Language Editor, and then drag it onto your chart from the Navigator panel. The setup takes about five minutes. Once it’s active, the Position Sizer panel lets you input your entry, stop-loss, and take-profit levels, select your order type, and set your risk percentage. Instantly, it returns the precise lot size that aligns with your risk management rules, and with a single click, it opens the trade directly from the panel.

This solves the friction problem. It removes the late-night calculator fumbles and ensures consistency across every trade. But there’s still another layer of friction that remains unsolved. Once your trade is open, and you’ve carefully sized your position using the EA, you’re left staring at the full MetaTrader terminal. The charts, the market watch, the open positions — it’s all there, demanding screen real estate and attention. You need to monitor the trade, check the floating P&L, and perhaps manage the stop-loss as the trade moves in your favor. But you don’t want to keep the entire terminal open, cluttering your workspace or drawing unwanted attention if you’re trading from a shared environment.

This is where Camovia Tray fits into the workflow. Rather than keeping the full MetaTrader window on your screen, Camovia Tray turns MT5 or MT4 into a system tray tool. The terminal can be hidden completely — removed from the taskbar and the Alt+Tab switching list — while you still maintain full visibility and control over your open positions. A quick hover over the tray icon shows you real-time quotes for your selected instruments, and the floating order panel gives you a clear view of your open trades: symbol, direction, lot size, entry price, and current profit and loss[citation:product_knowledge].

More importantly, Camovia Tray lets you manage those positions without reopening the terminal. If a trade is moving against your stop and you need to exit, you can close it with a two-step confirmation from the tray interface — no need to restore the MT5/MT4 window[citation:product_knowledge]. This makes the post-trade workflow smoother, especially for traders who prefer to check in on positions periodically rather than babysit screens all day.

Another practical advantage: Camovia Tray works with MT5 via a direct connection, and with MT4 through a one-time bridge EA installation (the CamoviaBridge, which takes about 30 seconds to set up)[citation:product_knowledge]. The data — your account balance, open positions, and quotes — stays entirely local, reading directly from your terminal without being sent to any remote server[citation:product_knowledge]. So your position sizing data, account equity, and trade activity remain private.

The combination is straightforward: use the Position Sizer EA to get your entry and lot size calculation right, execute the trade through your terminal, then hide MT5/MT4 and monitor or close the position through Camovia Tray. It’s a workflow designed for traders who want to minimize platform clutter without sacrificing access to critical trade information.