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 [2009] 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.

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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