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
Why Your Backtest Is Lying to You: Data Biases That Ruin Equity Research
Survivorship bias, look-ahead bias, point-in-time data, and the rest of the subtle ways your beautiful backtest is overstating returns. With concrete fixes for each.
2026-05-19 · 5 min read
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Finance
The Boring Math of Compound Returns (And Why Everyone Gets It Wrong)
Compound interest sounds like magic. The math is mundane and the most common rules of thumb are subtly wrong. Here's a calmer take on what compounding actually delivers.
2026-05-19 · 5 min read
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Finance
Index Funds, ETFs, Mutual Funds: What Actually Differs (and When It Matters)
The three labels overlap more than the marketing suggests. A developer-friendly breakdown of structure, tax treatment, and the cases where the difference actually changes your decision.
2026-05-19 · 5 min read
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Finance
Polygon vs Alpha Vantage: Which Stock Data API Fits a Side-Project Budget
Polygon and Alpha Vantage are the two common entry points for developer-side stock data. A side-by-side on free tiers, coverage, and developer experience — without the trading-edge hype.
2026-05-19 · 6 min read
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Finance
SEC EDGAR for Developers: The Free Fundamentals API Hiding in Plain Sight
Most stock-data tutorials skip past the one free, public, no-rate-limit source for US company filings. Here's how to read fundamentals straight from SEC EDGAR, JSON-first.
2026-05-19 · 5 min read
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Finance
What Diversification Actually Buys You (and What It Doesn't)
Diversification reduces idiosyncratic risk, not market risk. When the distinction matters, what correlation looks like under stress, and why 60/40 isn't a free lunch.
2026-05-19 · 5 min read
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Finance
What 'Rules-Based Investing' Actually Means (And What It Doesn't)
Rules-based investing isn't AI, isn't HFT, and isn't a guarantee. It's a behavioral discipline: decide the action before the event. Here's what counts as a rule, what doesn't, and how it actually fails.
2026-05-19 · 5 min read
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Finance
Why we're writing about investing on a developer tools blog
Tools, evidence, and disclosure are the same job whether the topic is a code editor or a brokerage account. Here's the editorial line for the new finance section.
2026-05-19 · 1 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.