The screen is definitely clear enough to view stock charts. And it's fairly large compared to the Sony Vaio UX, Fujitsu U810 and OQO model 2 also reviewed on this site, which means it's easier on the eyes.
I do recommend the current model (Q1 Ultra) over the original Q1 since the Ultra has a higher resolution display which means less scrolling.
-------------------- Lisa Gade Editor in Chief, MobileTechReview