I think this is a mistake. They already issued one correction from "20-member" to "20,000-member". The author seems to have serious problems with numbers. Look at the first paragraph:

> Facebook Inc took down a popular Wall Street discussion group, Robinhood Stock Traders, in a move that its founder on Thursday described as backlash for conversations buoying shares of GameStop Corp and other companies this week.

First, a typo, "buoying". But it also says "this week". So what they meant is probably Jan. 27.

Not a typo, a totally appropriate word. The conversations buoyed the shares, they did not buy them.

https://dictionary.cambridge.org/us/dictionary/english/buoyi...

Thanks, English is not my native language.

Hmm, good point, I didn't think of that possibility. It's a very confusing article, as I mentioned in a different comment: https://news.ycombinator.com/item?id=25954579

That's what got me confused too, the entire article makes zero sense if it was on Jan 7. Good catch though, I would have never noticed that.