Investing, for people who read the docs.
Tested reviews of investing tools, market essays grounded in evidence, and the occasional developer-to-investor crossover. No price predictions, no guaranteed returns.
Latest finance
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Finance
Building a Dividend Reinvestment Tracker in Python
A data model and sync loop for DRIP lots, cost basis, and yield on cost from a brokerage API, plus the corporate actions that break naive trackers.
2026-08-12 · 7 min read
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Finance
What IV Rank Tells You Before an Earnings Report
IV rank compresses a year of implied volatility into one number. How it is calculated, and the three checks that keep it from misleading you.
2026-08-12 · 7 min read
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Finance
Reading a 10-K: The Five Sections That Change a Thesis
Most of a 10-K is boilerplate carried over from last year. SEC endpoints let you diff filings instead of reading them front to back.
2026-08-12 · 7 min read
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Finance
Position Sizing: The Math Retail Investors Skip in 2026
Size each trade from risk, not conviction: the fixed-fractional formula, fractional Kelly, R-multiples, and drawdown survival math.
2026-06-22 · 8 min read
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Finance
Dollar-Cost Averaging vs Lump Sum: What the Math Really Says
A measured look at why lump-sum investing usually beats dollar-cost averaging on expected return, when DCA still makes sense, and how to decide for your own cash.
2026-06-22 · 7 min read
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Finance
What the Sharpe Ratio Actually Tells You
Excess return per unit of volatility -- what the number captures, the four assumptions that break it, and when to trust it.
2026-06-22 · 7 min read
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Finance
Tiingo vs Polygon.io: Market Data APIs in 2026
Pricing, rate limits, and data coverage compared for solo quant builders, plus which one fits a weekend backtester.
2026-06-22 · 7 min read
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Finance
Building a Portfolio Rebalancing Script in Python
Measure allocation drift, generate a self-funding trade list, and use threshold bands to avoid over-trading.
2026-06-22 · 7 min read
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Finance
Risk Parity for Retail Portfolios: A Developer's Guide
Risk parity allocates by risk contribution instead of dollars, so one volatile asset doesn't dominate. Includes implementation steps and common caveats.
2026-06-09 · 8 min read
What you won't find here
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No stock picks
No buy/sell calls, no target prices, no "this is the one" essays.
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No guaranteed returns
Past performance isn't predictive. We say so out loud.
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No tax or legal advice
Rules vary by jurisdiction. Ask a CPA, not a blog.