Fixed Ratio Sizing Demonstrator
Fixed ratio sizing, from Ryan Jones's "The Trading Game" (1999), grows position size in whole units of a starting size every time cumulative profit clears a fixed "delta" threshold - and each successive unit needs exactly that same delta again, not a proportionally larger one. That is the entire design: size compounds aggressively while the account is small relative to delta, then the rate of size increase tapers off relative to balance as more units stack up, because the money required for the NEXT unit stays flat while the account behind it keeps growing. Fixed fractional sizing behaves the opposite way - it risks a constant percentage of balance on every trade, so size grows smoothly and continuously with the account rather than in discrete jumps. Both methods are legitimate; they simply trade size growth for volatility of size growth in opposite directions, and the difference is easiest to see side by side rather than argued about in the abstract. This EA tracks cumulative closed profit from your own trade history (filtered by magic number if you want to isolate one system), computes what fixed ratio would currently recommend, computes what fixed fractional would recommend for the same balance and a configurable risk percentage, and shows both together along with how much more profit is needed before fixed ratio bumps up to the next unit. The fixed fractional comparison is deliberately built from tick value and tick size rather than a hardcoded contract size, because a hardcoded 100,000 unit contract silently mis- sizes metals, indices and JPY crosses - the same trap this catalogue avoids everywhere money is converted to lots. Notes and limitations This EA places no orders and manages no positions - it is a calculator only. Cumulative profit is read from closed trade history matching the filters, so a fresh account or a newly changed magic filter starts the progression from zero regardless of the account's actual longer history. Fixed ratio sizing can grow size very aggressively when delta is set small relative to typical trade profit; the demonstrator does not cap the number of units it will recommend, so choose delta deliberately rather than leaving the default unexamined.
Expert advisor · MT5 · v1.0 · Free
About Fixed Ratio Sizing Demonstrator
Fixed Ratio Sizing Demonstrator is a script for MetaTrader 5. It has 7 settings, such as Initial lots, Delta and Magic filter. MQL source code included.
Files in the download: FixedRatioSizerEa.ex5, FixedRatioSizerEa.mq5, FixedRatioSizerEa.txt.
Settings
| Setting | Default | What it does |
|---|---|---|
| Initial lots | 0.10 | Starting size - one "unit" in the fixed ratio progression |
| Delta | 1000.0 | Account currency of cumulative profit required per unit increase |
| Magic filter | -1 | Magic number whose closed history counts as cumulative profit, -1 = all |
| This symbol only | false | Restrict the profit tally to this chart's symbol only |
| Compare risk percent | 1.0 | Risk % of balance used for the fixed-fractional comparison |
| Compare stop pips | 20.0 | Stop distance used for the fixed-fractional comparison |
| Csv file name | FixedRatioSizerEa.csv | Log of both curves at each recompute, in MQL5\Files |
How to install
- Download the ZIP from your PolyMaria library and unzip it.
- In MetaTrader 5 open File → Open Data Folder, then go to MQL5 → Scripts.
- Copy the .mq5 file(s) there. Put any .mqh files in MQL5 → Include.
- Open the .mq5 file in MetaEditor and press Compile (F7) if MetaTrader does not show it.
- Drag the script onto a chart to run it once.
Tags: Risk & Lot Size · MT5 Expert Advisor · MQL5 Source Code