As the guys have said where you have an FX symbol the text displayed can be set by expression. There are currently gaps in the areas that can be set in this way which I've heard Qlik are going to be addressing.
I hope they do as in addition to eh use case you have mentioned I need to be able to localise my chart comments and currently its a bit hit and miss e.g. titles, subtitles, footnotes yes, dimensions, measures, sheet names no.
i think it can be archived using text box & variable. u can assign the variable value dynamically same will be displayed on the text box. but question is what is your definition of dynamic data. from where and how u will receive the data and when, where & how you want to show the data. based on that u can right the logic