Create a text element and add a bullet behavior. Uncheck 'set angle' on the behavior.
And, here's your code:
+ System: On start of layout
-> Text: Set position to (ViewportRight(0)+1, 0)
-> Text: Set Bullet speed to -150
+ System: Text.X+Text.Width+1 < ViewportLeft(0)
-> Text: Set X to ViewportRight(0)+1
This is a very, very basic 'ticker.' If your text is static, this will do the job. If your text changes, you're going to have to come up with your own way to set the width of the text box because that's how it decides when to reset back to the beginning.