That is a fantastic question. The simple answer here is that adding UTM parameters to a link will not affect search rankings. It won’t help you and it won’t hurt you. Google and Bing are aware of the fact that UTM parameters are used to track traffic. The search engines essentially overlook any UTM parameters when they crawl your website.
All that being said, links with little or no tracking characters on them look and feel more trustworthy than unruly links with strange looking strings of text and numbers. Adding tracking information to your links may psychologically affect people in a negative way, resulting in fewer clicks. That may be a bit of a reach, and it’s certainly a bit of speculation on our part, but if your link is at all affected by UTM parameters, this would be the reason why.