Gandalf Expert Advisor: Trend Smoothing Strategy

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The Gandalf Expert Advisor is inspired by a forum discussion.

Also recommended: Automated Live Testing for Expert Advisors on Demo Accounts - similar expert with strong performance on MetaTrader 5.

Note: Optimization is required!

The EA manages one buy position and one sell position simultaneously. These are two independent trades that remain open until closed by a predefined Take Profit or Stop Loss.

The trading logic is based on a two-parameter exponential smoothing of a time series. The smoothing considers two main factors:
1. Price position (parameter S)
2. Trend slope (parameter T)

The calculations utilize recurrence formulas:
S[n] = w * Y[n] + (1 - w) * (S[n-1] + T[n-1])
T[n] = t * (S[n] - S[n-1]) + (1 - t) * T[n-1]

The predicted value is calculated as: Y[n+1] = S[n] + T[n]

Source values for the first and second parameters can be derived from linear regression formulas.


Expert Advisor Inputs

For Long Positions:
- in_buy: Boolean, allows or disallows long positions.
- count_buy: Integer, the number of history bars used for time series smoothing.
- w_price: Float, the price factor.
- w_trend: Float, the trend factor.
- sl_buy: Integer, the stop loss level in pips.
- risk_buy: Float, the risk level as a percentage of free margin.

For Short Positions: The parameters in_sell, count_sell, m_price, m_trend, sl_sell, and risk_sell function similarly to their long position counterparts.


Optimization Process

Optimization is conducted in two distinct steps, initially using a fixed lot size (when risk_buy=0 and risk_sell=0).

Step 1 (Long Positions):
- Set in_buy=true and in_sell=false.
- Optimize count_buy from 3 to 120 (step 1).
- Optimize w_price and w_trend from 0.05 to 0.6 (step 0.01).
- Optimize sl_buy from 30 to 100 (step 1).

Step 2 (Short Positions):
- Set in_buy=false and in_sell=true.
- Optimize the remaining parameters similarly to Step 1.

Performance Notes:
The Expert Advisor demonstrates effective trading during clear trend periods on H4 and D1 timeframes, particularly for EURUSD. It is recommended to incorporate an additional filter using an indicator on higher timeframes to refine market entry signals. This strategy was last updated in 2026.

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• This tool is provided for educational and testing purposes only.
• Past performance does not guarantee future results.
• Trading involves substantial risk of loss. Use on a demo account first.
• Results may vary depending on market conditions, broker, and settings.
• We recommend thorough backtesting and forward testing before using with real funds.