I use the function reqMktData and it gets me the open/high/low/close with realtime data for stocks. however when I apply the same for the forex symbols, I only get bid and ask. how can I get the open for the day?
Sure but that will be between some arbitrary point in the day, and the next point 24 hours later. GAT
That's fine as long as arbitrary point is fixed to the same time of the day. I believe currency futures start trading at 6pm EST. This can be considered open price for the day.
you probably want to standardize on one of the fixing times https://www.bloomberg.com/markets/currencies/fx-fixings