“Few” is short for “few understand this” and is a common phrase found in most hardcore Bitcoiners and Twitter feeds.
It tends to be used in situations where Bitcoin has received another wave of FUD and the Bitcoiner on Twitter is saying something that is not meant to be common knowledge with the rest of the world or to provide a moonboy stance.
There are also satirical and ironic uses of the word “little” that you’ll likely come across as well.
“Influencers” will try to get some engagement on their profile by saying something odd, followed by “little” at the end.
Due to Twitter’s character limit, the phrase was shortened to “little” so that more vital characters could be used in the tweet for more important things.