Best Practices
Learn proven techniques and strategies for developing effective trading strategies with Lona.
Strategy Development Philosophy
Start Simple, Then Iterate
The most successful strategy development follows this pattern:
- Begin with Core Concept: Test the basic idea
- Validate Logic: Ensure it works as expected
- Refine Parameters: Optimize key values
- Add Filters: Improve signal quality
- Test Robustness: Verify across markets and timeframes
Golden Rule: A simple strategy that works beats a complex strategy that doesn’t.
The 80/20 Principle
80% of your results come from:
- ✅ Solid core logic
- ✅ Appropriate indicators
- ✅ Clear entry/exit rules
- ✅ Risk management (when needed)
20% of your results come from:
- ⚠️ Complex optimizations
- ⚠️ Micro-adjustments
- ⚠️ Minor refinements
Focus on the 80% first!
Interview Phase Best Practices
Communicate Clearly
Do:
✅ "Buy when the 10-period SMA crosses above the 30-period SMA"
✅ "Exit when RSI reaches 70"
✅ "Use 14-period RSI with 30/70 thresholds"Don’t:
❌ "Use moving averages" (which ones? what periods?)
❌ "Trade RSI" (how? what thresholds?)
❌ "Make it profitable" (not specific enough)Provide Context
Help Lona understand your reasoning:
Good:
"I want to use RSI for mean reversion. When RSI falls below 30,
the market is oversold. I want to buy when RSI crosses back above
30, signaling recovery. Exit when RSI reaches 70 (overbought)."Why it’s good:
- Explains the strategy type (mean reversion)
- Defines what indicators mean (oversold/overbought)
- Specifies exact entry/exit triggers
- Shows the logic flow
Answer Questions Completely
When Lona asks clarifying questions:
Effective Response:
Lona: "What moving average periods would you like?"
You: "Use 20 for the fast MA and 50 for the slow MA.
Both should be simple moving averages."Ineffective Response:
Lona: "What moving average periods would you like?"
You: "The usual ones" (ambiguous)Strategy Design Best Practices
Choose Appropriate Indicators
Match indicators to your strategy type:
Trend-Following:
- ✅ Moving Averages (SMA, EMA)
- ✅ MACD
- ✅ ADX
- ❌ RSI (momentum indicator)
- ❌ Stochastic (oscillator)
Mean Reversion:
- ✅ RSI
- ✅ Stochastic
- ✅ Bollinger Bands
- ❌ Moving Average Crossovers
- ❌ Trend indicators
Momentum:
- ✅ RSI
- ✅ MACD
- ✅ Rate of Change
- ❌ Mean reversion indicators
Use Logical Combinations
Good Combinations:
Trend Filter + Timing:
Trend: 50-period MA (identify direction)
Timing: MACD crossover (precise entry)
Logic: Only long when price > MA AND MACD crosses upMomentum + Confirmation:
Momentum: RSI for overbought/oversold
Confirmation: Volume spike
Logic: Buy on RSI < 30 AND volume > averageBad Combinations:
Conflicting Signals:
❌ Trend-following MA + Mean reversion RSI
(One says trend, other says reverse)Redundant Indicators:
❌ Three different moving averages (10, 20, 30 MA)
(All measure the same thing)Define Clear Exit Rules
Every strategy needs exits:
Good Exit Rules:
- ✅ “Exit when indicator gives opposite signal”
- ✅ “Close position when MA crosses below price”
- ✅ “Exit after holding for N bars”
- ✅ “Take profit at X% gain”
Poor Exit Rules:
- ❌ “Exit when profitable” (when exactly?)
- ❌ “Close if it drops” (how much?)
- ❌ “Exit soon” (not specific)
Parameter Selection
Start with Standard Values:
| Indicator | Standard Period | Rationale |
|---|---|---|
| SMA/EMA | 20, 50, 200 | Industry standard |
| RSI | 14 | Wilder’s original |
| MACD | 12, 26, 9 | Default settings |
| Bollinger Bands | 20, 2 | Standard deviation |
| Stochastic | 14, 3, 3 | Common settings |
Then Adjust Based on:
- Market volatility
- Your trading timeframe
- Backtest results
- Strategy responsiveness needs
Parameter Optimization
Systematic Testing Approach
Step 1: Baseline Test
Test with standard parameters
Document results
Establish baseline performanceStep 2: One Variable at a Time
Change only fast MA period: 5, 10, 15, 20
Keep slow MA constant at 50
Test each variation
Compare to baselineStep 3: Combine Best Values
Best fast MA: 15
Now test slow MA: 30, 50, 70, 100
Keep fast MA at 15
Find optimal combinationStep 4: Final Validation
Test best combination on different:
- Time periods
- Market conditions
- SymbolsAvoiding Over-Optimization
Warning Signs of Over-Optimization:
🚩 Too Perfect: 90%+ win rate, minimal drawdown 🚩 Too Specific: Works only with very precise parameters 🚩 Not Robust: Small parameter changes = dramatic performance drop 🚩 Curve Fitting: Optimized to every historical wiggle 🚩 Too Complex: 10+ parameters to tune
How to Avoid:
✅ Test Out-of-Sample: Reserve some data for validation ✅ Use Parameter Ranges: Strategy should work with similar values ✅ Cross-Validate: Test on different symbols/timeframes ✅ Simplicity First: Fewer parameters = more robust ✅ Economic Logic: Strategy should make intuitive sense
Parameter Ranges to Explore
Moving Averages:
Fast: 5-30 (try: 5, 10, 15, 20)
Slow: 30-200 (try: 30, 50, 100, 200)RSI:
Period: 2-30 (try: 7, 14, 21)
Oversold: 20-40 (try: 20, 25, 30)
Overbought: 60-80 (try: 70, 75, 80)Bollinger Bands:
Period: 10-30 (try: 10, 20, 30)
Std Dev: 1-3 (try: 1.5, 2.0, 2.5)Testing Best Practices
Data Selection
Use Representative Data:
✅ Include Different Market Conditions:
- Bull markets
- Bear markets
- Sideways/ranging markets
- High volatility periods
- Low volatility periods
✅ Adequate Time Period:
- Minimum: 2-3 years
- Recommended: 5+ years
- Include at least one full market cycle
✅ Multiple Symbols:
- Test on 3-5 different symbols
- Include correlated and uncorrelated markets
- Mix asset classes if possible
Minimum Sample Sizes
For reliable statistics:
| Trades | Reliability |
|---|---|
| < 20 | ❌ Not reliable |
| 20-50 | ⚠️ Minimal confidence |
| 50-100 | ✅ Moderate confidence |
| 100-200 | ✅ Good confidence |
| 200+ | ✅ High confidence |
If you have < 50 trades:
- Test on longer time periods
- Test on more symbols
- Question if strategy trades enough
- Consider adjusting sensitivity
Metric Interpretation
Focus on Risk-Adjusted Returns:
❌ Wrong Focus:
"This strategy returned 150%!"
(But with 80% drawdown...)✅ Right Focus:
"This strategy returned 35% with 12% max drawdown
and Sharpe ratio of 1.8"
(Sustainable risk/reward)Key Metrics Priority:
- Sharpe Ratio (risk-adjusted return)
- Maximum Drawdown (worst-case loss)
- Total Return (absolute performance)
- Win Rate (consistency)
- Profit Factor (wins vs losses)
Forward Testing Mindset
Remember:
- ✅ Past performance ≠ future results
- ✅ Backtest shows what COULD have happened
- ✅ Real trading has costs (fees, slippage)
- ✅ Market conditions change
- ✅ Strategy may need adaptation
Before Going Live:
- Paper trade for 30+ days
- Start with small position sizes
- Monitor for slippage/costs
- Be ready to adjust or stop
Iterative Development
The Development Cycle
1. Create → 2. Test → 3. Analyze → 4. Refine → repeatIteration Example:
Version 1:
Strategy: MA Crossover (10/30)
Result: 15% return, 25% drawdown
Analysis: Too many whipsaws in ranging marketsVersion 2:
Strategy: MA Crossover (10/30) + volume filter
Result: 22% return, 18% drawdown
Analysis: Better, but still some false signalsVersion 3:
Strategy: MA Crossover (20/50) + volume filter
Result: 28% return, 12% drawdown
Analysis: More stable, fewer trades but higher qualityWhen to Move Forward
A strategy is ready for next phase when:
✅ Logic makes intuitive sense ✅ Sharpe ratio > 1.0 (preferably > 1.5) ✅ Maximum drawdown tolerable (<20%) ✅ Sufficient trade count (>50 trades) ✅ Works across multiple symbols ✅ Performance stable across time periods
When to Pivot
Consider a new approach when:
❌ Strategy loses money consistently ❌ Win rate < 30% (unless huge winners) ❌ Maximum drawdown > 40% ❌ Performance extremely inconsistent ❌ No logical explanation for why it would work ❌ Can’t improve after 5+ iterations
Common Mistakes to Avoid
1. Over-Complicating
Mistake:
"Use MA crossover AND RSI AND MACD AND volume AND
price action AND support/resistance AND..."Better:
"Use MA crossover confirmed by volume"Why: More indicators ≠ better strategy. More complexity = more ways to fail.
2. Ignoring Drawdowns
Mistake:
"This returned 100%!"
(ignoring the 60% drawdown)Better:
"This returned 30% with only 10% drawdown"Why: You need to survive the drawdowns to see the returns.
3. Cherry-Picking Results
Mistake:
Testing only on bull market data
Testing only on one favorable symbol
Testing only on best time periodBetter:
Test across multiple:
- Market conditions
- Symbols
- Time periodsWhy: Real trading won’t be cherry-picked.
4. Parameter Over-Fitting
Mistake:
"It works perfectly with MA periods of 17.3 and 43.7!"Better:
"It works well with MA periods around 15-20 and 40-50"Why: Overly specific parameters won’t work in future.
5. Ignoring Transaction Costs
Mistake:
Strategy trades 50 times per day
Backtest shows 2% average profit per tradeReality:
Trading fees: 0.1% per trade
Slippage: 0.1% per trade
Net profit: 1.8% → becomes 1.2%
After 50 trades: costs eat significant portionBetter: Factor in costs from the start.
6. Abandoning Too Quickly
Mistake:
"First test didn't work, strategy is bad"Better:
"First test showed issues. Let me adjust
parameters and try different timeframes"Why: Good ideas often need refinement.
7. Chasing Perfect
Mistake:
Tweaking forever to get that extra 0.5% returnBetter:
Strategy is profitable and robust. Moving to
paper trading to validate in real marketWhy: Perfection is the enemy of progress.
Documentation and Organization
Keep a Trading Journal
Document Each Strategy:
Strategy Name: MA Crossover 20/50 v3
Date Created: 2024-01-15
Core Concept: Trend following with MA crossover
Indicators: 20 SMA, 50 SMA
Entry: 20 crosses above 50
Exit: 20 crosses below 50
Parameters Tested: 10/30, 15/40, 20/50, 25/75
Best Results: 20/50 on SPY (28%, Sharpe 1.8, DD 12%)
Notes: Works well in trending markets, avoid ranging periods
Next Steps: Add volume filter to reduce whipsawsTrack Your Learning
What Worked:
- Document successful approaches
- Note which indicators work well together
- Record optimal parameter ranges
What Didn’t Work:
- Save failed strategies too (learn from mistakes)
- Note why they failed
- Avoid repeating same mistakes
Advanced Tips
Combining Strategies
Once you have multiple successful strategies:
Portfolio Approach:
Strategy A: Trend-following (35% allocation)
Strategy B: Mean-reversion (35% allocation)
Strategy C: Momentum (30% allocation)
Benefit: Diversification reduces overall riskAdaptive Strategies
Concept: Adjust strategy based on market conditions
Example:
If market volatility low:
→ Use mean reversion
If market volatility high:
→ Use trend followingImplementation: Create separate strategies, deploy based on conditions
Walk-Forward Analysis
Advanced Testing Method:
- Optimize on Period 1 (e.g., 2020)
- Test on Period 2 (e.g., 2021)
- Re-optimize on Periods 1-2
- Test on Period 3 (e.g., 2022)
- Continue rolling forward
Benefit: Simulates realistic optimization and testing flow
Mindset and Discipline
Patience is Key
✅ Strategy development takes time ✅ Good ideas need refinement ✅ Testing reveals issues ✅ Iteration improves results
Realistic Expectations
Achievable Goals:
- 15-30% annual return
- Sharpe ratio > 1.0
- Maximum drawdown < 20%
- Win rate 45-55%
Unrealistic Goals:
- 100%+ annual return
- 90%+ win rate
- Never losing trades
- Zero drawdown
Continuous Learning
✅ Study why strategies work/fail ✅ Learn from each backtest ✅ Read about trading concepts ✅ Understand market dynamics ✅ Keep improving your approach
Quick Reference Checklist
Before Creating Strategy
- Clear idea of core concept
- Appropriate indicators identified
- Entry/exit rules defined
- Parameter ranges considered
During Interview
- Communicated clearly
- Answered all questions
- Specified exact values
- Explained logic
After Code Generation
- Reviewed code explanation
- Verified parameters make sense
- Understood strategy logic
Before Execution
- Appropriate data selected
- Parameters configured
- Initial capital set
- Ready to analyze results
After Results
- Analyzed all metrics
- Studied equity curve
- Checked trade count
- Evaluated drawdowns
- Documented findings
Optimization Phase
- Changed one variable at a time
- Tested systematically
- Validated on multiple markets
- Avoided over-fitting
- Kept strategy simple
What’s Next?
Now that you know best practices:
- Troubleshooting: Solve common issues
- Glossary: Reference for terms
- Creating Strategies: Apply these practices
Next: Review Troubleshooting for solutions to common problems.