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Part of the Sanchayam series. Expands Stage 2 of the corporate actions pipeline. What Sanchayam computes FIFO cost basis and XIRR from historical prices. Prices are fetched by trading symbol. When a company changes its symbol (INFOSYSTCH to INFY) or its name (Hindustan Lever to Hindustan Unilever), a price lookup by the current symbol silently misses every week before the change. The backfill pipeline fixes this with an alias table. One row per symbol-and-name period, so each historical date range is queried with the symbol that was live at the time. Yahoo Finance supplies splits and bonuses. NSE corporate announcements supply name changes, symbol changes, and mergers. ...

Part of the Sanchayam series. Overview Sanchayam has two deployable components: Backend: Node.js process running as a systemd service behind nginx Frontend: Static React build deployed to S3, served via CloudFront Prerequisites A Linux server with Node.js 18+ and PostgreSQL An AWS account with an S3 bucket and CloudFront distribution for the frontend A domain with DNS pointing to your server (for TLS) A Twelve Data API key (free tier at twelvedata.com - 8 calls/minute) Backend Clone and install: ...

Part of the Sanchayam series. The Problem When an Indian equity undergoes a 2-for-1 stock split, a holding that showed 100 shares should now show 200 shares at half the price. The historical lot prices need to be adjusted retroactively - otherwise the cost basis and XIRR calculations are wrong. Similarly, when a company changes its name or trading symbol (Infosys was previously INFOSYSTCH, Hindustan Unilever was Hindustan Lever), historical price data retrieved by the current symbol will not cover periods before the name change. ...

Part of the Sanchayam series. Why Friday Portfolio performance is tracked week by week, not day by day. Daily snapshots would generate a large amount of data for a view that is displayed weekly at best. Friday is chosen because Indian markets close at 3:30 PM IST on Friday. The snapshot cron runs at 11:00 AM UTC, which is 4:30 PM IST - 30 minutes after market close, giving price feeds time to settle. ...

Part of the Sanchayam series. What XIRR Is XIRR (extended internal rate of return) is an annualized return that accounts for the timing of cash flows. Simple absolute return tells you what percentage you gained on an investment. XIRR tells you what annual rate of return is equivalent to the actual cash flows you made - buys, sells, and the current value - given exactly when each one happened. A 50% gain over 10 years is very different from a 50% gain over 2 years. XIRR captures that difference. It is the standard metric for evaluating the performance of an investment portfolio with irregular cash flows over time. ...