AMarquee panels are fairly narrow, depending on how many panels are used and the width available.  Be sure to refine your character count to a minimum and you can also hit return and start a new line of text. Note: any spaces will allow words to wrap to the next line.  In addition, check your theme width controls and increase until there's enough content width available.  When viewing in some mobile devices in portrait orientation, this can be a problem as width is limited, so please try to choose small words or abbreviations, if possible.  And of course, rotating to landscape orientation in mobile browsers will always provide more width for viewing.