Lot Size Roundup & Margin Check with Down-Size Option
Written By Ehsaan XP
Last updated 3 months ago
⚠️ Disclaimer: This guide is for educational and informational purposes only. It does not constitute financial advice, investment advice, or a recommendation to trade. Trading involves risk, including the potential loss of capital. All examples are illustrative. Platform features described here are execution and risk-management utilities, not indicators of future performance.
Overview
You know the frustration.
Trade idea is solid, the indicator aligns, execution timing is perfect—and then the broker rejects the trade with an error. In most cases, the culprit is simple: insufficient free margin, or the final lot size falls below the broker's minimum requirement.
But what’s not simple is catching that issue before the order is sent. That’s exactly what this new feature set is designed to do: act as a pre-flight safety system that checks, adjusts, and protects every order automatically. Think of it as a co-pilot whose only job is to stop avoidable execution failures.
The Pre-Flight Checklist (How the System Thinks)
Before any order is sent, it must pass three checks:
Is the lot size below the broker’s minimum?
Is there enough free margin for this lot size?
If not, can the lot size be safely reduced?
Common Use Cases
Preventing broker minimum lot rejections
Salvaging trades during drawdowns
Running multiple strategies on constrained capital
Avoiding margin exhaustion during volatility spikes
Debugging execution issues with full clarity
Feature 1: Lot Size Roundup
How to find: Strategy Settings → Money Management → Lot Size Controls
What It Solves
Brokers reject trades that don’t meet minimum lot requirements.
How It Works
If your strategy calculates a lot size below the broker's minimum:
The system automatically rounds it up to the minimum allowed size
Then the system checks if there is enough free margin to open that trade with the minimum lot size
Example
Strategy calculates: 0.0013 lots ( that is rounded by lot step to 0)
Broker minimum: 0.01 lots
Adjusted automatically to: 0.01 lots
No rejection. No manual fixes.
It’s a smart fix — but here’s what traders need to understand:
That increase also changes your risk.
A 0.010 lot is more than seven times the exposure of a 0.0013 lot. So while the feature keeps your trade alive, it also increases your potential drawdown if the trade goes against you.
Let’s put that into perspective.
If your stop loss was calculated to risk $1 on 0.0013 lots, and your trade is now executing at 0.010 lots — your real risk is now over $7.
Critical Safety Rule
If rounding up causes a margin shortfall, the trade isn’t submitted to the broker:
Example
The system rounded the lot size to the broker's minimum lot size of 0.01.
Required margin to open the trade is 16190 JPY.
Free margin on the user account is 9721 JPY.
Feature 2: Downsize (Margin-Based Auto Adjustment)
How to find: Strategy Settings → Money Management → Lot Size Controls
This feature is especially designed to prevent the “Insufficient funds” error returned by the broker.
Behind every rejection is plain math.
Example from a real log:
Required margin to open trade: $10329
Available free margin: $10000
The order never had a chance.
The problem isn’t strategy logic—it’s execution mismatch between:
calculated lot size
broker rules
available margin
The solution is not manual babysitting.
It’s automated pre-trade intelligence.
What It Solves
Trades that are valid but too large for current free margin.
How It Works
When a trade fails the margin check:
The system calculates the maximum safe lot size, taking into account the broker lot step requirements and the allowed minimum margin level
Adjusts the order to fit the available margin
Sends the corrected order automatically
Example (Successful Save)
Requested lot: 1
Required margin: $10362
Free margin: $10000
Adjusted lot: 0.7
New required margin: $7692
Trade opens successfully
Without down size, this trade would have failed.
When Down Size Will NOT Save the Trade
Downsize is smart—but intentionally conservative.
The system may still not submit a downsized trade for the following reasons:
The maximum reduced lot size is smaller than the broker's minimum
There is no free margin to open even the minimum allowed lot size
The downsized lot cannot maintain the minimum margin level percent and free margin requirements at the same time
Examples:
The system attempted to reduce the lot size to meet free margin requirements, but the available margin was too low—the calculated lot size fell below the broker's minimum. In this case, the downsize option cannot submit a valid order.
Down size wasn’t submitted to the broker because of the minimum margin level % requirement:
Margin level % = (Equity/Margin) * 100 %:
Equity = 6500 USD
Margin = used + for opened order = 4464 + 350 = 4814 USD
Calculated margin level % = 135 %
Minimum margin level % = 150 %
This is not a failure—it’s correct risk enforcement.
Troubleshooting
Trade still blocked?
Check free margin at execution time
Review broker minimum lot size
Verify minimum margin level isn’t too restrictive
Unexpected lot size changes?
Review whether roundup or down size triggered
Check logs for the exact adjustment reason
No adjustment attempted?
Feature may be disabled
Broker minimum increase may have caused a hard stop
Summary: A Smarter Execution Layer
With these controls in place, your strategy gains:
Far fewer “Not enough money” errors
Automated, rule-based risk adjustment
Full transparency into execution decisions
Protection against broker rule mismatches
Entry logic finds opportunities.
Execution intelligence keeps them alive.
Your strategy doesn’t just trade anymore—it adapts.
And that’s what separates fragile automation from professional-grade systems.