Most online forums have a 'reputation indicator' that let's people in a thread know something - either a quantitative post count, or some other indication, e.g. "veteran", based on number of 'accepted answers to questions' or 'likes', etc.
PredictIt has the opportunity to do this, but with a small symbol indicating net gain/loss.
Let users opt in.
The vibrant discussions in each market are a huge part of the PredictIt community success; those of up many thousands should have a visible indicator, that we are expert Predictors. Let the big dogs strut
PredictIt uses disqus.com for its comment section and at disqus.com you can see the number of comments a user has posted, how many likes the poster got, and even read the comments at other websites, if the poster hasn't opted out of that being possible.
. . . It is an open question if frequent posters are also big bettors on average. If you bet a lot, maybe you rather don't want to tell everyone your strategy and thoughts. Personally, I post comments after I've placed my bets, but sometimes I change my bets afterwards.