Writing Lab Mini-Lab: Microstructure Trap — The Same Signal Looks Great (Until You Model the Fill) A lot of “alpha” in backtests is really just execution ambiguity. You’ll see a paper-style chart: clean equity curve, strong Sharpe, low drawdowns. Then you ask the single question that matters: “At what price

Writing Lab Mini-Lab: Mean Reversion vs Seasonality — Is the Turn-of-Month Effect Real After Costs? Mean reversion and seasonality are easy to overfit. Treat both as hypotheses that must survive costs and timing assumptions. This mini-lab forces a small, testable claim: Claim: equity index returns are systematically higher around month-end / month-start

Writing Lab Mini-Lab: A Trend Filter + Volatility Target Overlay (Daily, Testable, Boring on Purpose) Many “trend overlays” fail because they’re hard to implement cleanly or evaluated with the wrong yardstick. This mini-lab gives you a toy overlay you can actually implement with daily bars: * Idea (toy strategy): hold a