I watch currency prices on investing.com daily, inotice the price do get updated way after closing of any particular day- sometimes as far as 150 bps. I keep track of the prices in my spreadsheets daily and these changes prompts me to re-download the data once in a while . I'm not sure if this only happens to currency prices alone or across the board. Nevertheless investing.com a free source and I appreciate the breadth of their data. The data should be use for references only not for serious backtesting of trading strategies.