Open/high/low/close in bar data vs bid/ask in tick data

In bar data there are open, high, low, and close prices for a time period, and in tick data there are bid and ask prices for each tick. I can see how a open, high, low, and close price could be calculated from bid and ask prices separately, but I’m not sure what the open, high, low, and close mean outside of the bid/ask context. How are the open, high, low, and close prices in bar data calculated? Is each the difference between the bid/ask? Thanks for explaining this.

Hello,

there can be differences in tick data format, what is the source you use? is it QuantDataManager or TickDownloader or any other?

Generally tick data does not contain OHLC prices because theres no point for them

I use TickDownloader. My understanding is that TickDownloader downloads tick data and if OHLC data are requested then it will create the OHLC data from the tick data. Can you explain how TickDownloader creates OHLC from tick data?

Hello, yes, TickDownloader first download tick data then OHLC are generated.

You can use QuantDataManager instead to download 1 minute data which is faster then generate OHLC data for required timeframe

It looks like TickDownloader generates the bar OHLC exclusively from tick bid amounts. Another logic is described at https://quant.stackexchange.com/questions/41247/when-converting-tick-to-ohlc-which-field-do-i-use-for-open-and-close-bid-or-as. Thanks.