Numbers from 2019 → 2020
Revenue = $78m to $161m
Users = 30m → 42m
Losses. = $13.6m → $15.8m
They doubled the money they brought in but still managed to lose more than the year before 
this while only adding 4 courses (not languages). Not sure where this revenue went?
My biggest concern is that they’re trading at 31x revenue while the closest comparison I could think of, Coursera (NYSE.COUR) is trading at 14 x revenues.
There really aren’t a lot of public EdTech companies that I found who are similar enough to DuoLingo, The competition RosettaStone, Babbel & Busuu are all private. Some more analysiswould be needed before making a judgement and as always this isn’t advice and do your own research 
