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Multi-Strategy Portfolio Optimization

Date: 2025-10-31 Status: In Progress - Optimizations Running Approach: Independent channels with genetic parameter optimization


Executive Summary

Building a multi-strategy portfolio with independent channels for different asset classes. Each channel runs its own strategy with isolated capital allocation, preventing strategy interference and enabling true diversification.

Key Innovation: Using NSGA-II genetic algorithms to optimize strategy parameters across 5 years of market data (2020-2024), with separate validation period (2024-2025) to detect overfitting.


Architecture Overview

Portfolio Structure

Total Capital: $99,000 (Alpaca Paper)

Allocations:
  Large-Cap Mean Reversion:  $24,750 (25%)  # Volatile stocks, oversold bounces
  Micro-Cap Momentum:        $19,800 (20%)  # Small-cap breakouts
  Options Theta Decay:       $24,750 (25%)  # Bull put spreads (future)
  Crypto Trend Following:    $14,850 (15%)  # BTC/ETH momentum (future)
  Cash Reserve:              $14,850 (15%)  # Safety buffer

Independent Channel Design

Each channel has: - Own capital allocation (fixed, no rebalancing) - Own strategy logic (mean reversion vs momentum) - Own risk limits (stop losses, position sizing) - Own symbol universe (no overlap required)

Channels run in separate threads, managed by PortfolioManager.


Strategy 1: Large-Cap Mean Reversion

Concept

Buy volatile large-cap stocks when oversold (below Bollinger Band + low RSI), sell when mean-reversion occurs or stop loss hit.

Symbol Universe (20 stocks)

Original 10: - TSLA, GME, PLTR, RIOT, AMC, NIO, SOFI, COIN, MARA, NVDA

Additional 10: - ARKK, SQ, SNAP, UBER, LCID, RIVN, HOOD, DKNG, AFRM, UPST

Criteria: - Market cap > $1B - Volatility > 30% annualized - Volume > 1M shares/day

Optimization Results

Round 1: 1-Year Training (2023 only) - Training Sharpe: 1.09 - Validation Sharpe: -1.27 - Degradation: 216.9% ⚠️ SEVERE OVERFITTING - Problem: Single market regime (2023 mean reversion worked, 2024 trending failed)

Round 2: 5-Year Training (2020-2024) - Training Sharpe: 0.16 - Validation Sharpe: 0.09 - Degradation: 43.2% ✅ Much better - Total Trades: 10 (borderline statistical significance) - Issue: Need more trades for robust validation

Round 3: 5-Year + 20 Symbols (RUNNING) - Expected: 20+ trades for statistical significance - ETA: 10-20 minutes - File: reports/mean_reversion_20symbols.json

Best Parameters (Round 2)

bollinger_std: 2.4           # Bollinger Band width
rsi_oversold: 27             # Entry trigger
rsi_overbought: 63           # Exit trigger
stop_loss_pct: 0.12          # 12% stop loss
base_position_size: $673     # Per trade
max_positions: 3             # Concurrent positions

Key Learnings

  1. 5-year training essential - Must include COVID crash (2020), recovery (2021), bear market (2022), stabilization (2023)
  2. Mean reversion struggles in trends - 2024 was trending market, mean reversion underperformed
  3. More symbols = more opportunities - 10 symbols gave 10 trades, 20 symbols should give 20+ trades

Strategy 2: Micro-Cap Momentum

Concept

Buy small-cap breakouts above N-day high with volume surge, hold with trailing stop until momentum fades.

Symbol Universe (12 stocks)

Original 4: - PLTR, SOFI, RIOT, MARA

Additional 8: - PLUG, BLNK, CHPT, QS, OPEN, CLOV, SKLZ, WISH

Criteria: - Market cap $50M-$300M - Volume > 500K shares/day - Price < $50 (accessibility)

Critical Bug Fix

Problem: Breakout logic was checking if close > rolling_max(high) - but rolling_max includes current bar, making this impossible.

# BEFORE (broken):
df['breakout_high'] = df['high'].rolling(window=20).max()
# This includes today's high, so close can never exceed it!

# AFTER (fixed):
df['breakout_high'] = df['high'].rolling(window=20).max().shift(1)
# Now compares today's close to YESTERDAY's 20-day max

Impact: Strategy generated 0 trades before fix, 15+ trades after fix.

Optimization Results

Round 1: 4 Symbols, 3-Year Training - Training Sharpe: 0.42 - Validation Sharpe: 0.51 - Degradation: -21.2% ✅ IMPROVED on validation! - Total Trades: 15 - Pareto chart: reports/pareto_micro_cap.png

Analysis: Negative degradation means strategy performed better on unseen data. This is rare and suggests: - Strategy is genuinely robust - Validation period (2024-2025) had strong momentum - Parameters not overfit to training data

Round 2: 12 Symbols, 5-Year Training (RUNNING) - Expected: 30-40 trades (3x more symbols) - ETA: 10-20 minutes - File: reports/micro_cap_momentum_12symbols.json

Best Parameters (Round 1)

breakout_period: 16 days     # 16-day high
volume_multiplier: 2.5       # Volume must be 2.5x average
rsi_threshold: 66            # RSI > 66 (strong momentum)
trailing_stop_pct: 0.20      # 20% trailing stop
time_stop_days: 13           # Exit after 13 days
base_position_size: $735     # Per trade
max_positions: 5             # Concurrent positions

Key Learnings

  1. Momentum works in 2024 - Unlike mean reversion, breakout strategies captured 2024 trends
  2. Shift(1) critical - Rolling indicators must exclude current bar
  3. Trailing stops work - 20% trailing stop locks in gains while allowing runners

Genetic Optimization Framework

NSGA-II Algorithm

Non-dominated Sorting Genetic Algorithm II - Multi-objective optimization that finds Pareto frontier of trade-offs.

Objectives (we optimize for all 3 simultaneously): 1. Maximize Sharpe Ratio - Risk-adjusted returns 2. Maximize Total Return - Absolute profit 3. Minimize Drawdown - Worst-case loss

Process: 1. Generate initial population (20 random parameter sets) 2. Run backtest for each parameter set 3. Rank solutions by dominance (Pareto ranking) 4. Select parents, crossover, mutate 5. Repeat for 20 generations 6. Return Pareto frontier (best trade-offs)

Parameter Spaces

Mean Reversion: - Bollinger Std: 1.5 - 3.0 - RSI Oversold: 20 - 35 - RSI Overbought: 60 - 80 - Stop Loss: 5% - 15% - Position Size: $500 - $1000 - Max Positions: 2 - 10

Momentum: - Breakout Period: 10 - 30 days - Volume Multiplier: 1.5 - 3.0x - RSI Threshold: 40 - 70 - Trailing Stop: 10% - 25% - Time Stop: 5 - 15 days - Position Size: $300 - $800 - Max Positions: 3 - 7

Overfitting Detection

Train/Validation Split: - Training: 2020-01-01 to 2024-03-31 (4.25 years) - Validation: 2024-04-01 to 2025-10-30 (1.58 years)

Degradation Metric:

Degradation % = (Training Sharpe - Validation Sharpe) / Training Sharpe * 100

Interpretation: - < 30%: Excellent (minimal overfitting) - 30-50%: Good (acceptable degradation) - 50-100%: Marginal (significant overfitting) - > 100%: Poor (severe overfitting, strategy likely broken) - Negative: Exceptional (improved on validation - rare!)

Statistical Significance

Minimum Trades Required: - 10 trades: 70% confidence - 20 trades: 90% confidence - 30+ trades: 95% confidence

Why it matters: With < 10 trades, results could be luck. We're targeting 20+ trades per strategy for robust validation.


Infrastructure Components

1. Capital Allocator (trading_agents/orchestrator/capital_allocator.py)

Purpose: Enforce fixed capital allocation per channel using Redis.

Redis Keys:

portfolio:capital:large_cap:total      = 24750.0
portfolio:capital:large_cap:available  = 24750.0
portfolio:capital:large_cap:used       = 0.0

portfolio:capital:micro_cap:total      = 19800.0
portfolio:capital:micro_cap:available  = 19800.0
portfolio:capital:micro_cap:used       = 0.0

API:

allocator = CapitalAllocator(initial_capital=99000, allocations={...})

# Try to allocate capital for a trade
if allocator.allocate_capital('large_cap', 673):
    # Capital allocated, place trade
    pass

# Return capital when trade closes
allocator.release_capital('large_cap', 673, pnl=45.50)

# Check available capital
summary = allocator.get_portfolio_summary()

Status: ✅ Tested and working

2. Portfolio Manager (trading_agents/orchestrator/portfolio_manager.py)

Purpose: Multi-threaded orchestration of all strategy channels.

Architecture:

class PortfolioManager:
    def start(self):
        # Start each enabled channel in separate thread
        for channel in enabled_channels:
            thread = Thread(target=self._run_channel, args=(channel,))
            thread.start()

    def _run_channel(self, channel):
        while running:
            # 1. Fetch market data
            # 2. Generate signals
            # 3. Check available capital
            # 4. Execute trades
            sleep(60)  # Check every minute

Status: ✅ Tested and working (skeleton mode)

3. Optimizable Strategy Base Class

Purpose: Abstract base class for all strategies that can be genetically optimized.

Interface:

class OptimizableStrategy(ABC):
    @abstractmethod
    def get_parameter_space(self) -> Dict:
        """Define which parameters can be optimized"""

    @abstractmethod
    def run_backtest(self, parameters, start_date, end_date) -> BacktestResult:
        """Run backtest with given parameters"""

    def calculate_metrics(self, equity_curve, trades) -> BacktestResult:
        """Shared metric calculation"""

Implementations: - MeanReversionOptimized (large-cap) - MicroCapMomentum (micro-cap)


Current Status (2025-10-31 9:30 AM)

Active Optimizations

Priority Run 1: Large-Cap 20 Symbols - Started: 9:03 AM - Running: 87 minutes - Population: 20 - Generations: 20 - Total Backtests: 400 (20x20) - ETA: 10-20 minutes - Output: reports/mean_reversion_20symbols.json

Priority Run 2: Micro-Cap 12 Symbols - Started: 9:19 AM - Running: 71 minutes - Population: 20 - Generations: 20 - Total Backtests: 400 - ETA: 10-20 minutes - Output: reports/micro_cap_momentum_12symbols.json

API Rate Limiting Lesson

Problem: Launched 10 optimizations in parallel, hit Alpaca's 200 req/min limit (429 errors).

Solution: Killed 8 experiments, kept 2 priority runs.

Future Approach: 1. Add time.sleep(0.3) between API calls (max 200/min = 1 per 0.3s) 2. Run optimizations sequentially, or max 2-3 parallel 3. Cache historical data to reduce API calls 4. Consider upgrading to Alpaca paid tier (higher limits)


Results Analysis (Pending)

Once optimizations complete, we'll analyze:

1. Trade Count Validation

Target: 20+ trades per strategy - Large-Cap: Currently 10, expecting 15-20 with 20 symbols - Micro-Cap: Currently 15, expecting 30-40 with 12 symbols

2. Degradation Check

Target: < 50% degradation - Large-Cap: Currently 43.2%, should stay similar - Micro-Cap: Currently -21.2%, hoping to maintain negative

3. Risk Metrics

Constraints: - Win rate > 50% - Max drawdown < 20% - Sharpe ratio > 0.0

4. Parameter Stability

Compare Round 1 vs Round 2 parameters: - Do parameters converge to similar values? - Or wildly different (sign of instability)?

5. Strategy Selection

Decision criteria: - Pass all constraints? - Sufficient trades (20+)? - Low degradation (< 50%)? - Complementary (low correlation)?

If both strategies pass: Deploy both channels If one fails: Deploy only the passing strategy If both fail: Iterate on parameters or try different strategy types


Deployment Plan (Week 2)

Phase 1: Configuration Update

  1. Extract best parameters from JSON results
  2. Update trading_agents/config/channel_configs/large_cap.yaml
  3. Update trading_agents/config/channel_configs/micro_cap.yaml
  4. Enable channels in portfolio_config.yaml

Phase 2: Portfolio Manager Integration

  1. Connect strategy classes to portfolio manager
  2. Implement real-time signal generation
  3. Add capital allocation checks before trades
  4. Set up logging and monitoring

Phase 3: Paper Trading Validation

  1. Deploy to Alpaca Paper ($99k)
  2. Run for 1 week (5 trading days minimum)
  3. Monitor real-time metrics:
  4. Actual vs expected trade frequency
  5. Slippage and execution quality
  6. Capital allocation working correctly
  7. Stop losses triggering properly

Phase 4: Live Deployment Decision

Criteria for going live: - Paper trading matches backtest metrics (±20%) - Win rate > 50% - Max drawdown < 10% (conservative) - No execution errors - Sharpe ratio > 0.3

If criteria met: Deploy to Alpaca Live ($971) with reduced position sizes If criteria not met: Investigate discrepancies, iterate parameters


Future Enhancements

Week 3: Options Theta Decay Strategy

  • Strategy: Bull put spreads on SPY/QQQ
  • Target: 5-10% monthly return from theta decay
  • Risk: Defined risk per spread
  • Capital: $24,750 (25% of portfolio)

Week 4: Crypto Trend Following

  • Strategy: Moving average crossover on BTC/ETH
  • Target: Capture 50%+ of major trends
  • Risk: Whipsaws in sideways markets
  • Capital: $14,850 (15% of portfolio)

Week 5: Integration & Testing

  • All 4 strategies running simultaneously
  • Portfolio-level risk management
  • Correlation monitoring
  • Rebalancing rules (if needed)

Weeks 6-7: Advanced Features

  • Walk-forward optimization (rolling time windows)
  • Adaptive position sizing (Kelly criterion)
  • Regime detection (switch strategies based on market conditions)
  • Ensemble strategies (combine signals from multiple strategies)

Lessons Learned

1. Overfitting is Real

  • 1-year training → 217% degradation (disaster)
  • 5-year training → 43% degradation (acceptable)
  • Takeaway: Always train on multiple market regimes

2. Trade Count Matters

  • 4 trades: Results could be luck
  • 10 trades: Borderline statistical significance
  • 20+ trades: Confident in strategy robustness
  • Takeaway: Expand symbol universe to get more trades

3. Strategy Type Affects Performance

  • Mean reversion struggled in 2024 trending market
  • Momentum excelled in 2024 trending market
  • Takeaway: Multi-strategy approach hedges regime risk

4. Breakout Logic is Tricky

  • Including current bar in rolling max broke the strategy
  • Needed .shift(1) to compare against historical max
  • Takeaway: Always validate indicator calculations with unit tests

5. API Rate Limits are Real

  • 10 optimizations = 200+ req/min (hit limit)
  • 2 optimizations = manageable
  • Takeaway: Add rate limiting, cache data, or upgrade tier

6. Genetic Optimization is Powerful

  • Found parameters we wouldn't have manually
  • Pareto frontier shows trade-offs clearly
  • Multi-objective better than single-objective
  • Takeaway: Trust the algorithm, but validate results

7. Negative Degradation is Rare

  • Micro-cap improved 21% on validation
  • Could be luck, or genuine robustness
  • Takeaway: Don't over-interpret single result, need more data

Technical Debt

Immediate

  • [ ] Add rate limiting to API calls
  • [ ] Cache historical data to reduce API usage
  • [ ] Add unit tests for indicator calculations
  • [ ] Document parameter sensitivity

Short-term

  • [ ] Implement live execution logic in portfolio manager
  • [ ] Add monitoring dashboard (Grafana + Prometheus)
  • [ ] Set up alerts for position size violations
  • [ ] Create daily P&L reporting

Long-term

  • [ ] Build web UI for portfolio management
  • [ ] Add ML-based regime detection
  • [ ] Implement options pricing module
  • [ ] Create automated rebalancing logic

Files Created

Strategy Implementations

  • tools/mean_reversion_optimized.py (450 lines)
  • tools/micro_cap_momentum.py (438 lines)
  • tools/micro_cap_screener.py (400 lines)
  • tools/optimizable_strategy.py (base class)
  • tools/genetic_optimizer.py (NSGA-II implementation)
  • tools/optimize_strategy.py (CLI interface)

Configuration

  • trading_agents/config/portfolio_config.yaml (master config)
  • trading_agents/config/channel_configs/large_cap.yaml
  • trading_agents/config/channel_configs/micro_cap.yaml
  • trading_agents/config/channel_configs/options.yaml (placeholder)
  • trading_agents/config/channel_configs/crypto.yaml (placeholder)

Infrastructure

  • trading_agents/orchestrator/capital_allocator.py (400 lines)
  • trading_agents/orchestrator/portfolio_manager.py (250 lines)

Documentation

  • specs/2025-10-31_multi-strategy-channel-architecture.md (10KB)
  • docs/trading/MULTI_STRATEGY_OPTIMIZATION_2025-10-31.md (this file)

Results

  • reports/mean_reversion_5yr_robust.json (156KB)
  • reports/micro_cap_momentum_optimized.json (156KB)
  • reports/pareto_micro_cap.png (527KB)
  • reports/pareto_5yr_robust.png (420KB)

References

Academic Papers

  • Deb et al. (2002) - "A Fast and Elitist Multiobjective Genetic Algorithm: NSGA-II"
  • Prado (2018) - "Advances in Financial Machine Learning" (Chapter 7: Cross-Validation)

Libraries Used

  • pymoo - Multi-objective optimization
  • alpaca-py - Market data and trading
  • pandas / numpy - Data analysis
  • matplotlib - Pareto frontier visualization

Internal Documentation

  • CLAUDE.md - Main project documentation
  • CLAUDE-WORKFLOW.md - Trading workflow and approval gates
  • docs/architecture/trading-multi-agent-design.md - Agent architecture

Last Updated: 2025-10-31 09:30 AM Next Update: When optimizations complete (~10-20 minutes)