Methods
Time series, risk measures, backtesting discipline, and the statistics that keep an analysis honest.
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Real versus nominal: deflating a series correctly, and six mistakes
From January 2021 to August 2026, real hourly pay fell 0.8% by the CPI and rose 1.7% by the PCE price index. How to deflate, checked against the BLS, and six traps.
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Bond math from first principles: price, yield, duration, convexity
Price, yield to maturity, Macaulay and modified duration, and convexity derived and coded from scratch, then applied to the Treasury par curve of 2026-09-09.
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Value at Risk three ways, backtested on the S&P 500
Historical, parametric normal, and Cornish-Fisher VaR computed on ten years of FRED's S&P 500 series, then backtested day by day with the Kupiec coverage test.
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Log returns, simple returns, and the compounding errors people make
Simple and log returns on ten years of FRED's S&P 500 series: the sum identity, variance drag, the size-of-move gap, and the mistakes each choice invites.
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Sharpe, Sortino, and max drawdown computed by hand on the S&P 500
Sharpe, Sortino, and maximum drawdown worked step by step in Python on ten years of FRED's S&P 500 series, with a 3-month Treasury risk-free rate, year by year.
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Backtest overfitting: the deflated Sharpe ratio and a simulation
Why the best of many backtests looks good even when every strategy is noise: a simulation you can run, plus the deflated Sharpe ratio applied to it.