Deepseek

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. 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. ...