I'm a web developer responsible for creating a website that has a section which contains the stock information of a certain company. This information is retrieved through an API which a stock exchange company provides (Tadawul All Share (TASI))
I realized that for some days the prices shown in the Historical Data chart are different from any of the prices contained in Historical Data table for example here are the data for a specific day ( 20-05-2018 )
My question is: what does the price in the historical chart refer to. I realize most of the prices in the historical chart match the 'close price'.. but as there are many times that the price is much different from the close price, I want to make sure.
and if it refers to the close price what could be the reason for it to be different from the close price for some days? is it an error?