Tag: Stock Data API
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Alpha Vantage to yfinance Migration: 3 Breaking Changes
Alpha Vantage to yfinance migration breaks position sizing in 3 subtle ways. Timezone drift, NaN handling, and adjusted close differences explained.
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yfinance vs Alpha Vantage vs Polygon: Real Cost Per 1M Calls
yfinance is free but breaks twice a year. Alpha Vantage costs $1,389 per million calls. Polygon offers $0-$299 tiers that actually scale. Real numbers.
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Stock Data API Debugging: 5 Silent Failures You’ll Hit
Stock APIs return 200 OK with corrupt data. Detect split adjustments, survivorship bias, and timezone drift before they ruin your backtest.