# ACB v5 Implementation on Nautilus-Dolphin

**Date:** 2026-02-19  
**Version:** v5 (Empirically Validated)  
**Status:** Production Ready

---

## Overview

The Adaptive Circuit Breaker (ACB) v5 has been integrated into the Nautilus-Dolphin trading stack. This implementation provides position-sizing protection based on external market stress indicators.

### Key Features

- **Position Sizing Only**: Affects trade size, not trade selection (win rate invariant at 46.1%)
- **External Factor Based**: Uses funding rates, DVOL, FNG, taker ratio
- **Empirically Validated**: 1% fine sweep across 0-80% (62 cut rates tested)
- **v5 Configuration**: 0/15/45/55/75/80 cut rates (beats v2 by ~$150 on $10k)

---

## ACB v5 Configuration

### Cut Rates by Signal Count

| Signals | Cut Rate | Description |
|---------|----------|-------------|
| 0 | 0% | No protection (normal market) |
| 1 | 15% | Light protection (mild stress) |
| 2 | 45% | Moderate protection |
| 3 | 55% | High protection (crash level) |
| 4 | 75% | Very high protection |
| 5+ | 80% | Extreme protection |

### External Factors Monitored

| Factor | Threshold | Weight |
|--------|-----------|--------|
| Funding (BTC) | <-0.0001 (very bearish) | High |
| DVOL (BTC) | >80 (extreme), >55 (elevated) | High |
| FNG (Fear & Greed) | <25 (extreme fear) | Medium (needs confirmation) |
| Taker Ratio | <0.8 (selling pressure) | Medium |

---

## Files Added/Modified

### New Files

1. **`nautilus/adaptive_circuit_breaker.py`**
   - `AdaptiveCircuitBreaker`: Core ACB logic
   - `ACBConfig`: Configuration dataclass
   - `ACBPositionSizer`: Integration wrapper
   - `get_acb_cut_for_date()`: Convenience function

2. **`tests/test_adaptive_circuit_breaker.py`**
   - Comprehensive unit tests
   - Integration tests (Feb 6 scenario)
   - Validation tests

### Modified Files

1. **`nautilus/strategy.py`**
   - Added ACB integration in `DolphinExecutionStrategy`
   - Modified `calculate_position_size()` to apply ACB cuts
   - Added ACB stats logging in `on_stop()`

---

## Usage

### Basic Usage (Automatic)

The ACB is **enabled by default** and automatically applies cuts to position sizing:

```python
# In your strategy config
config = {
    'acb_enabled': True,  # Default: True
    # ... other config
}

strategy = DolphinExecutionStrategy(config)
```

When a signal is received, the strategy will:
1. Calculate base position size (balance × fraction × leverage)
2. Query ACB for current cut rate based on external factors
3. Apply cut: `final_size = base_size × (1 - cut_rate)`
4. Log the ACB application

### Manual Usage

```python
from nautilus_dolphin.nautilus.adaptive_circuit_breaker import (
    AdaptiveCircuitBreaker, get_acb_cut_for_date
)

# Method 1: Direct usage
acb = AdaptiveCircuitBreaker()
cut_info = acb.get_cut_for_date('2026-02-06')
print(f"Cut: {cut_info['cut']*100:.0f}%, Signals: {cut_info['signals']}")

position_size = base_size * (1 - cut_info['cut'])

# Method 2: Convenience function
cut_info = get_acb_cut_for_date('2026-02-06')
```

### Disabling ACB

```python
config = {
    'acb_enabled': False,  # Disable ACB
    # ... other config
}
```

---

## Empirical Validation

### Test Results (1% Fine Sweep)

| Cut Rate | ROI | MaxDD | Sharpe |
|----------|-----|-------|--------|
| 0% | 8.62% | 18.3% | 1.52 |
| 15% | 7.42% | 15.8% | 1.51 |
| 45% | 4.83% | 10.5% | 1.46 |
| 55% | 3.93% | 8.6% | 1.43 |
| 75% | 2.01% | 5.0% | 1.28 |
| 80% | 1.50% | 4.1% | 1.19 |

### v5 vs v2 Comparison

| Config | Ending Capital | MaxDD | Winner |
|--------|----------------|-------|--------|
| v5 (0/15/45/55/75/80) | **$10,782** | 14.3% | **v5** |
| v2 (0/30/45/55/65/75) | $10,580 | 11.7% | |

**v5 wins by $202 (1.9%)** - validated across multiple market scenarios.

### Feb 6/8 Crash Validation

- **Feb 6**: 3+ signals detected → 55% cut applied → Saved $2,528 vs no-CB
- **Feb 8**: 3+ signals detected → 55% cut applied → Saved $468 vs no-CB

---

## Configuration Options

### ACBConfig Parameters

```python
from nautilus_dolphin.nautilus.adaptive_circuit_breaker import ACBConfig

config = ACBConfig(
    # Cut rates (v5 optimal - empirically validated)
    CUT_RATES={
        0: 0.00,
        1: 0.15,
        2: 0.45,
        3: 0.55,
        4: 0.75,
        5: 0.80,
    },
    
    # Signal thresholds
    FUNDING_VERY_BEARISH=-0.0001,
    FUNDING_BEARISH=0.0,
    DVOL_EXTREME=80,
    DVOL_ELEVATED=55,
    FNG_EXTREME_FEAR=25,
    FNG_FEAR=40,
    TAKER_SELLING=0.8,
    TAKER_MILD_SELLING=0.9,
    
    # Data path
    EIGENVALUES_PATH=Path('.../correlation_arb512/eigenvalues')
)
```

---

## Monitoring and Logging

### Log Output Example

```
[INFO] ACB applied: cut=55%, signals=3.0, size=1000.00->450.00
[INFO] Position opened: BTCUSDT, entry=$96,450, TP=$95,495

...

[INFO] ACB stats: calls=48, cache_hits=45, 
       cut_distribution={0: 25, 0.15: 10, 0.45: 8, 0.55: 4, 0.75: 1}
```

### Statistics Available

```python
# Get ACB statistics
stats = strategy.acb_sizer.acb.get_stats()
print(f"Total calls: {stats['total_calls']}")
print(f"Cache hit rate: {stats['cache_hit_rate']:.1%}")
print(f"Cut distribution: {stats['cut_distribution']}")
```

---

## Testing

### Run Unit Tests

```bash
cd nautilus_dolphin
python -m pytest tests/test_adaptive_circuit_breaker.py -v
```

### Test Scenarios

1. **Normal Market**: 0 signals → 0% cut
2. **Mild Stress**: 1 signal → 15% cut
3. **Moderate Stress**: 2 signals → 45% cut
4. **High Stress**: 3 signals → 55% cut
5. **Extreme Stress**: 4+ signals → 75-80% cut

### Feb 6 Integration Test

```python
# Simulate Feb 6 conditions
cut_info = get_acb_cut_for_date('2026-02-06')
assert cut_info['signals'] >= 2.0
assert cut_info['cut'] >= 0.45
```

---

## Architecture

```
┌─────────────────────────────────────────────────────────────┐
│                 DolphinExecutionStrategy                    │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│  ┌─────────────────┐      ┌─────────────────────────────┐  │
│  │  Signal Received │─────>│  calculate_position_size()  │  │
│  └─────────────────┘      └─────────────────────────────┘  │
│                                       │                     │
│                                       ▼                     │
│                           ┌─────────────────────────────┐  │
│                           │   ACBPositionSizer          │  │
│                           │   - get_cut_for_date()      │  │
│                           │   - apply_cut_to_size()     │  │
│                           └─────────────────────────────┘  │
│                                       │                     │
│                                       ▼                     │
│                           ┌─────────────────────────────┐  │
│                           │  AdaptiveCircuitBreaker     │  │
│                           │  - load_external_factors()  │  │
│                           │  - calculate_signals()      │  │
│                           │  - get_cut_from_signals()   │  │
│                           └─────────────────────────────┘  │
│                                       │                     │
│                                       ▼                     │
│                           ┌─────────────────────────────┐  │
│                           │  External Factor Files      │  │
│                           │  (correlation_arb512/...)   │  │
│                           └─────────────────────────────┘  │
│                                                             │
└─────────────────────────────────────────────────────────────┘
```

---

## Best Practices

### 1. Always Keep ACB Enabled
```python
# DON'T disable ACB unless you have a specific reason
config = {'acb_enabled': False}  # NOT recommended
```

### 2. Monitor Cut Distribution
```python
# Check that cuts are being applied reasonably
stats = acb.get_stats()
if stats['cut_distribution'][0.80] > 10:  # Too many extreme cuts
    print("Warning: High frequency of extreme cuts")
```

### 3. Cache Hit Rate
```python
# Cache should be >80% for same-day lookups
assert stats['cache_hit_rate'] > 0.8
```

---

## Troubleshooting

### Issue: ACB Not Applying Cuts

**Symptoms**: All trades at full size, no ACB logs

**Solutions**:
1. Check `acb_enabled` is True in config
2. Verify external factor files exist in `EIGENVALUES_PATH`
3. Check logs for "ACB applied" messages

### Issue: Always 0% Cut

**Symptoms**: ACB always returns 0% cut

**Solutions**:
1. Check external factor files are being loaded
2. Verify factor values (funding, DVOL, FNG, taker)
3. Check signal calculation thresholds

### Issue: Too Many Extreme Cuts

**Symptoms**: Frequent 75-80% cuts

**Solutions**:
1. Check external factor data quality
2. Verify FNG confirmation logic (requires other signals)
3. Adjust thresholds if needed

---

## References

- **Original Analysis**: `ACB_1PCT_SWEEP_COMPLETE_ANALYSIS.md`
- **v2 vs v5 Comparison**: `analyze_v2_vs_v5_capital.py`
- **Empirical Results**: `vbt_results/acb_1pct_sweep_*.json`
- **Feb 6/8 Validation**: `ACB_CUT_RATE_EMPRICAL_RESULTS.md`

---

## Contact

For issues or questions about the ACB implementation, refer to:
- `nautilus_dolphin/nautilus/adaptive_circuit_breaker.py`
- `nautilus_dolphin/tests/test_adaptive_circuit_breaker.py`

---

**End of ACB Implementation Documentation**