Author-Only Appendix · Product Strategy Notes

Book-to-Product Bridge: Features from the Original Manuscript to Consider for EasyCompare

A catalog of features, metrics, and workflows mentioned in the original StockQuanta / CoinQuanta book draft, how we adapted them in Chapters 5 to 9 today, and how we can add them natively into EasyCompare and BetterThanSPY.

While adapting Chapters 5 through 9 from the original manuscript, several sections referenced specific features or planned capabilities from StockQuanta / CoinQuanta. In the live chapters, we grounded every chart and table in what the EasyCompare Go backend (http://localhost:8081) computes today (net_return, cagr, volatility, sharpe_ratio, period_max_drawdown, trend_ath_atl, and spy_correlation). Below are the manuscript features that are not yet in EasyCompare, along with concrete recommendations for how adding them would strengthen both the product and its tie-in with the book.

Book Chapter & Concept What the Manuscript Described Current State in EasyCompare Product Recommendation for EasyCompare
Ch 5: Extrapolated Crash / Tail Risk Estimate "Crash risk can be approximated by the previous distribution of performance volatility and extrapolating it to simulate extreme scenarios (see Appendix A)." Go backend computes exact historical period_max_drawdown and underwater drawdown series, plus annualized volatility. Add an optional Estimated Tail Loss (99% CVaR / Cornish-Fisher or 3-Sigma Stress Drop) column in the Go backend (metrics.go). This solves the exact problem noted in Ch 5: when a young stock hasn't lived through a 2008 crash yet, its volatility distribution still warns the user of its potential tail drop.
Ch 5: Sortino Ratio (Downside-Only Risk-Adjusted Return) "Look at risk-adjusted measures of performance that include Sharpe Ratio and Sortino Ratio." Go backend currently returns sharpe_ratio (using total volatility). Compute Sortino Ratio in the Go engine (dividing excess CAGR by downside deviation of negative daily returns only). High-growth winners like NVDA or LLY have big upside spikes that inflate standard volatility; Sortino avoids penalizing upside volatility.
Ch 6: Pairwise Correlation Matrix & Portfolio-Level Correlation "Build a performance profile for your portfolio and compute correlation of candidate assets to your entire portfolio, plus detect asset clones inside your portfolio." Go backend computes each ticker's correlation against SPY (spy_correlation). 1. Add a Pairwise Correlation Heatmap / Clone Detector tab in EasyCompare for the currently selected tickers (highlighting pairs with >80% correlation as "Clones" and <20% as "True Diversifiers").
2. In BetterThanSPY, allow sorting discovery candidates by lowest correlation to the user's current ticker list.
Ch 7: Inverse-Volatility Position Sizer ("Risk-Balanced Allocator") "Allocate your capital in an inversely proportional manner to risk or volatility... e.g. $10,000 across assets." We built an interactive 2-asset Risk-Balanced Sizing widget inside Chapter 2 (guide.js), but /app itself doesn't yet have an allocation calculator. Add a one-click "Risk-Balance My Tickers ($10,000)" popover or modal in EasyCompare's table header: given the N tickers currently on screen, show their Equal-Dollar Risk Share vs. their Inverse-Volatility Dollar Allocation (just like Figure 7.1).
Ch 7: Composite Rank (QuantaRank / EasyRank) "QuantaRank balances Performance, TrendScore, Volatility, Risk-Adjusted Performance, and Correlation into a single composite rank." Users can sort by any individual column in /app and /betterthanspy, and BetterThanSPY has multi-factor filtering. Add a Composite Quant Score (0–100) column in EasyCompare and BetterThanSPY that combines percentile ranks of Sharpe Ratio (35%), TrendScore (25%), Low Max Drawdown (20%), and Low SPY Correlation (20%), with preset weights ("Balanced", "Momentum", "Defensive").
Ch 8: Recency-Weighted, Time-Chunked TrendScore "TrendScore chunks the price time series to weight recent sub-periods higher while rewarding consistency and low path volatility." Go backend computes trend_ath_atl (based on distance from ATL/ATH extremes). Enhance trend_ath_atl (or add trend_score) in the Go engine by splitting the selected window into 4 to 8 sub-chunks, computing the sign and R² of log-price regression with exponential recency weights, and scaling by inverse volatility.

Summary of How These Strengthen the Book-to-App Loop

Right now, every figure in Chapters 1 through 9 already links directly into EasyCompare with the exact tickers and date windows pre-loaded. If we add even two or three of the items above (such as the Inverse-Volatility Portfolio Sizer modal, the Pairwise Correlation / Clone Detector, and Sortino Ratio), every single specialized concept from your original manuscript will have a 1-to-1 interactive tool inside EasyCompare.