Amihud Lambdas Estimator
Amihud studies the positive relationship between absolute returns and illiquidity. In particular, he computes the daily price response associated with one dollar of trading volume, and argues its value is a proxy of price impact.
Despite its apparent simplicity, Hasbrouck  found that daily Amihud’s lambda estimates exhibit a high rank correlation to intraday estimates of effective spread.
This indicator is based on Advances in Financial Machine Learning 2018 - Marcos Lopez de Prado book, Page 288.
This code can run slow when using big timeframes, it use copytick to get dollar volume, in a next version I will implement a temporary indicator to cumulative sum this values as a buffer