Sanchayam

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. ...

Part of the Sanchayam series. Why FIFO FIFO (first in, first out) is the standard cost basis method for Indian equities and mutual funds for tax purposes. When you sell shares, the oldest lots you bought are assumed to be the ones sold first. The cost basis of those oldest lots determines your taxable gain. Sanchayam implements FIFO at sell time: when a sell lot is recorded, the backend walks the buy lots in chronological order, consuming them until the sell quantity is satisfied, and computes the aggregate cost. ...