Technical Articles

Deep dives into quantitative methods, model validation techniques, and the 43 S-series modules that power V7. Written to share learnings and contribute to the quant community.

Regime Detection
7 min readJan 20, 2025

Why Hurst Exponent Beats Static Regime Labels

How the Hurst exponent provides real-time regime classification that adapts exit giveback thresholds, improving exit timing by 18% in trending markets.

#Hurst Exponent#Regime Detection#Exit Timing
Regime Detection
6 min readJan 18, 2025

ATR Percentile Ranking for Volatility Regime Classification

How ATR percentile-based volatility classification reduces drawdown by adjusting position sizing and signal thresholds during vol spikes.

#Volatility#ATR#Risk Management
Risk Management
7 min readJan 16, 2025

Detecting Correlation Breakdowns Before They Cascade

Rolling correlation monitoring across asset clusters that detects breakdown events and prevents cascading multi-position drawdowns.

#Correlation#Portfolio Risk#Tail Risk
Model Validation
12 min readJan 15, 2025

Regime-Conditioned Block Bootstrap for Trading Strategy Validation

How to validate trading strategies using Monte Carlo simulation with regime-conditional resampling. Addresses the limitation of naive bootstrap that ignores market regime changes.

#Monte Carlo#Bootstrap#Regime Detection#Validation
Regime Detection
6 min readJan 14, 2025

How ADX Regime Classification Filters 22% of Losing Trades

ADX-based momentum regime classification that identifies choppy markets and filters out low-quality signals, removing 22% of losing trades.

#ADX#Momentum#Trade Filtering
Risk Management
7 min readJan 12, 2025

Fractional Kelly Meets Drawdown Zones: Optimal Sizing Under FTMO

Quarter-Kelly position sizing integrated with DD-triggered risk zones for optimal capital allocation under FTMO constraints.

#Kelly Criterion#Position Sizing#FTMO
Risk Management
6 min readJan 10, 2025

Anti-Martingale Sizing: Compound When Hot, Protect When Cold

Anti-Martingale position scaling that increases risk during winning streaks and decreases during losing streaks, adding 8% to total R.

#Position Sizing#Risk Management#Streak Analysis
Risk Management
6 min readJan 8, 2025

The Circuit Breaker That Makes FTMO Breach Nearly Impossible

Hard daily and total loss limits with safety buffers that achieved zero FTMO breaches across 7.5 years and 4,505 trades.

#Circuit Breaker#FTMO#Risk Management
Signal Processing
5 min readJan 6, 2025

When a 1978 Indicator Outperforms Custom Neural Features

ADX values as direct L1 XGBoost features, ranking in the top 5 by SHAP importance in 4 of 6 asset clusters.

#ADX#Feature Engineering#XGBoost
Regime Detection
7 min readJan 4, 2025

Letting K-Means Define Market States Nobody Named

Unsupervised K-Means clustering on market features achieving 0.68 silhouette score, enabling regime-conditional alpha generation.

#K-Means#Unsupervised Learning#Regime Detection
Regime Detection
7 min readJan 2, 2025

Deep Autoencoders as Early Warning Systems for Regime Shifts

Autoencoder reconstruction error detects regime transitions 2-3 bars before traditional indicators, providing early warning for parameter adjustment.

#Autoencoder#Anomaly Detection#PyTorch
Model Validation
6 min readDec 30, 2024

Rolling SHAP Analysis: Catching Feature Decay Before It Catches You

Rolling SHAP value analysis that tracks which features drive L1 decisions over time, detecting feature decay and concept drift.

#SHAP#Feature Importance#Concept Drift
Risk Management
6 min readDec 28, 2024

When EURUSD and GBPUSD Both Signal: Choosing the Stronger Bet

Limits simultaneous exposure to correlated positions, reducing correlated position exposure by 40% through signal strength tiebreaking.

#Correlation#Position Limits#Diversification
ML Architecture
8 min readDec 26, 2024

Teaching a PPO Agent When to Exit: Reinforcement Learning for Trade Management

Proximal Policy Optimization RL agent for exit timing that improved average exit R from 0.78 to 0.92 through hold-or-exit decision optimization.

#Reinforcement Learning#PPO#Exit Timing
Signal Processing
6 min readDec 24, 2024

Not All Signals Are Created Equal: Calibrated Confidence Ranking

Calibrated logistic regression weighting of L1 signal confidence, where top-quintile signals achieve 67% win rate versus 52% for bottom quintile.

#Calibration#Signal Quality#Logistic Regression
Trade Execution
6 min readDec 22, 2024

Sub-Bar Entry Timing: Getting 0.3 ATR Better Prices

Sub-bar entry timing using order flow features that waits for pullbacks within signal bars, achieving 0.3 ATR better entry prices on average.

#Entry Timing#Order Flow#Execution
Trade Execution
5 min readDec 20, 2024

The Spread Tax: Why 12% of Your Trades Should Never Happen

Filters trades when bid-ask spread exceeds 2x normal, eliminating 12% of trades with poor fills during illiquid periods.

#Spread#Execution Quality#Filtering
ML Architecture
6 min readDec 18, 2024

When One Model Is Not Enough: Bootstrap Aggregation for Signal Confidence

Bagged ensemble of L1 models using bootstrap aggregation that reduces signal variance by 25% and provides prediction confidence intervals.

#Bootstrap#Ensemble#Variance Reduction
Signal Processing
7 min readDec 16, 2024

Adding Mean Reversion to a Momentum System: Cointegrated Pairs as Diversifier

Cointegration-based pairs trading using Engle-Granger test, identifying 12 validated pairs that added 15.2R as a supplementary strategy.

#Pairs Trading#Cointegration#Statistical Arbitrage
Risk Management
5 min readDec 14, 2024

The Day I Had 14 Open Positions: Why Concentration Limits Exist

Caps maximum open positions per cluster and total, preventing overexposure during high-signal periods and keeping portfolio heat at 3% max.

#Position Limits#Concentration Risk#Portfolio Heat
Model Validation
6 min readDec 12, 2024

Your Backtest Is Too Optimistic: Building an Honest Slippage Model

Realistic slippage model accounting for market impact, spread variation, and order size effects, adjusting backtest results by -2.1R for honesty.

#Slippage#Transaction Costs#Backtest Integrity
Validation
10 min readDec 10, 2024

Why PBO Matters: Detecting Backtest Overfitting

Deep dive into Probability of Backtest Overfitting (PBO) and why it is essential for distinguishing genuine alpha from data mining artifacts.

#PBO#Overfitting#Validation#Statistics
Model Validation
7 min readDec 10, 2024

PBO 0.112: The One Number That Keeps Me Honest

Probability of Backtest Overfitting calculation using combinatorially symmetric cross-validation, achieving PBO=0.112 well below the 0.5 threshold.

#PBO#Overfitting#CSCV
ML Architecture
6 min readDec 8, 2024

Transfer Learning for Financial Time Series: Pre-Training the Exit LSTM

Pre-trained LSTM on raw price sequences before fine-tuning for exit prediction, achieving 40% faster convergence through transfer learning.

#LSTM#Transfer Learning#Pre-training
Infrastructure
5 min readDec 6, 2024

The Bug That Took Two Months: Why Feature Preprocessing Is Not Optional

Consistent feature scaling between training and inference using saved Z-score parameters, eliminating train/test preprocessing mismatch.

#Feature Engineering#Preprocessing#Data Pipeline
Model Validation
7 min readDec 4, 2024

Twelve Folds of Evidence: Walk-Forward Validation That Earns Trust

Anchored walk-forward optimization with expanding window confirming OOS performance within 13% of IS across 12 independent folds.

#Walk-Forward#Cross-Validation#Out-of-Sample
Infrastructure
5 min readDec 2, 2024

The Most Boring Module That Saved My Backtest

Multi-timeframe data alignment ensuring M15, H1, H4, D1 bars are properly synchronized with zero data alignment errors.

#Data Pipeline#Multi-Timeframe#Timezone
Model Validation
6 min readNov 30, 2024

Detecting Strategy Decay Before It Costs Real Money

60-day rolling Sharpe ratio with decay detection alerts that flags significant deviations from historical baseline performance.

#Sharpe Ratio#Performance Monitoring#Decay Detection
Infrastructure
5 min readNov 28, 2024

Why Every Trade Needs a Paper Trail

Automated trade logging capturing all 38 feature values, model confidence scores, and execution details for every trade.

#Logging#Audit Trail#Debugging
Signal Processing
6 min readNov 26, 2024

When Three Timeframes Agree: The 9-Point Win Rate Edge

M15/H1/H4 directional confluence checking that achieves 64% win rate on aligned signals versus 55% on single-timeframe.

#Multi-Timeframe#Confluence#Signal Quality
Trade Execution
5 min readNov 24, 2024

Why I Turn Off My Trading System During NFP

Calendar-based filter blocking entries around major economic releases, avoiding average 1.2R loss per major news event.

#News Filter#Economic Calendar#Risk Avoidance
Risk Management
6 min readNov 22, 2024

The Gap That Changes Everything: Sizing for Overnight Risk

Reduces position size for trades held overnight to account for gap risk, reducing overnight gap losses by 60%.

#Overnight Risk#Gap Risk#Position Sizing
System Design
15 min readNov 20, 2024

Building a 3-Layer ML Trading Pipeline

Architectural decisions behind separating signal generation (L1), entry timing (L2), and exit management (L3) in the V7 Engine.

#Architecture#ML Pipeline#System Design
Model Validation
6 min readNov 20, 2024

OOS Sharpe at 87% of IS: Walk-Forward Results That Hold Up

Full walk-forward validation framework testing strategy robustness across multiple market regimes with OOS Sharpe at 87% of IS.

#Walk-Forward#Validation#Out-of-Sample
Model Validation
5 min readNov 18, 2024

The Invisible Bias That Inflates Everything

Validates backtest against survivorship-free instrument universe, confirming zero survivorship bias across all 4,505 trades.

#Survivorship Bias#Data Integrity#Backtest Validation
Model Validation
6 min readNov 16, 2024

Eighteen R Down the Drain (And Why That Is Fine)

Realistic commission and swap cost model per instrument accounting for spread, commission, and overnight financing at -18.3R total.

#Transaction Costs#Spread#Swap Costs
Risk Management
5 min readNov 14, 2024

Trading Your Own Equity Curve: The Meta-Strategy Layer

Trades the equity curve itself, reducing size when equity drops below its moving average and increasing when above.

#Equity Curve#Meta-Strategy#Adaptive Sizing
Trade Execution
6 min readNov 12, 2024

Not All Hours Are Created Equal: Session-Based Entry Filtering

Filters entries by trading session with session-filtered win rate of 62% versus 54% for all-hours trading.

#Session Filter#Time-of-Day#Liquidity
Signal Processing
6 min readNov 10, 2024

Putting More Money Where It Is Working: Dynamic Cluster Allocation

Dynamic allocation across asset clusters based on recent momentum and regime signals, overweighting performing clusters.

#Cluster Rotation#Asset Allocation#Momentum
ML Architecture
6 min readNov 8, 2024

When Your Model Says 70% but Reality Says 55%: Fixing Probability Calibration

Platt scaling and isotonic regression to calibrate L1 probability outputs, reducing calibration error from 8% to 2%.

#Calibration#Platt Scaling#Probability
Infrastructure
4 min readNov 6, 2024

Speed Is a Feature: 10x Faster Data Loading with Parquet

High-performance data caching using Apache Parquet achieving 10x faster data loading compared to CSV.

#Parquet#Data Pipeline#Performance
Model Validation
6 min readNov 4, 2024

Features Do Not Last Forever: Monitoring Predictive Power Over Time

Tracks individual feature predictive power over time, identifying 2 features with decaying alpha for potential removal.

#Feature Decay#SHAP#Model Monitoring
Risk Management
7 min readNov 2, 2024

DD-Triggered Risk Scaling: The Module That Keeps You in the Game

Four-zone adaptive risk protocol scaling from 0.30% down to 0.15% based on drawdown severity, achieving 0.08% FTMO breach probability.

#Drawdown#Risk Scaling#FTMO#Recovery
Model Validation
7 min readOct 30, 2024

Simulating 5,000 Alternate Realities: Block Bootstrap Monte Carlo

Block bootstrap Monte Carlo with regime-conditioned resampling validating 0.08% breach probability across 5,000+ simulations.

#Monte Carlo#Block Bootstrap#Tail Risk
Model Validation
6 min readOct 28, 2024

Your Backtest Is Lying (By a Known Amount)

Calculates realistic 15% performance haircut accounting for data mining, multiple testing, and implementation shortfall.

#Haircut#Data Mining Bias#Multiple Testing
Model Validation
7 min readOct 26, 2024

Testing Every Possible Way to Be Wrong: CSCV for Strategy Evaluation

Combinatorially Symmetric Cross-Validation testing all possible IS/OOS combinations, producing foundation for PBO=0.112 calculation.

#CSCV#PBO#Overfitting Detection
Feature Engineering
8 min readOct 5, 2024

Hurst Exponent for Market Regime Classification

Using Hurst exponent to detect trending vs mean-reverting regimes and adapt strategy parameters accordingly.

#Hurst#Regime Detection#Time Series
Machine Learning
11 min readSep 12, 2024

LSTM Exit Timing: Formulating Exits as Sequence Prediction

How LSTM networks can predict optimal exit timing by learning from trade trajectory sequences.

#LSTM#Neural Networks#Exit Strategy

43 S-Series Modules Documented

Every module in the S-series architecture has its own technical article explaining why it exists, how it works, and the measurable impact on performance.

Explore S-Series Architecture →