yfdata.download VectorBT Pro: Handling
What happens when your backtest runs on data with invisible gaps? If you rely on yfdata.download vectorbtpro without cleaning, your strategy might be tr...
What happens when your backtest runs on data with invisible gaps? If you rely on yfdata.download vectorbtpro without cleaning, your strategy might be trading on ghosts. Missing ticks and price gaps are silent killers of algorithmic performance. They distort indicator calculations, create false signals, and ruin the accuracy of your historical simulation. In the world of quantitative research, data integrity is not optional; it is the foundation of every profitable edge. This guide explores how to identify and fix these data issues using Python, specifically focusing on the capabilities of VectorBT PRO and standard data cleaning techniques. Missing data is any gap in a time series where price information is absent for a specific interval. In tick data, this means a trade did not occur; in OHLC bars, it means the bar is missing entirely. When you pull data from free sources like Yahoo Finance, you often encounter irregular intervals. A 1-minute bar might be missing because no trade occurred, or the API simply failed to return it. If your strategy relies on a 14-period Moving Average, a missing bar shifts the calculation window.