Reddit stock fell 5%+ on Friday after Meta launched a standalone app for online forums, called Forum; Reddit's stock is now down almost 40% this year (Jonathan Vanian/CNBC)

Jonathan Vanian / CNBC: Reddit stock fell 5%+ on Friday after Meta launched a standalone app for online forums, called Forum; Reddit's stock is now down almost 40% this year — Reddit shares fell about 6% on Friday on concern that a new app from Meta called Forum could create an alternative avenue for internet users …