My study related impact reduce tick size towards liquidity. Im having a problem in collecting the intraday data especially number shares traded at bid and ask price. Thus, i decided to change it instead spread and depth since its very hard for me to compile the data. I had asked Thomson Reuters, however they don't sell it to individually and its costing around usd2000-3000. Therefore i decided to change it into daily data. Please suggest me proxy to liquidity using daily data. Thanks for the idea.