Over 700 million shares were traded last week, so even if every WSB user bought 10 shares, that wouldn't account for close to a majority of the activity.
Volume is meaningless, as the same share might be traded back and forth several times, e.g HFT or order flow buyers flipping stocks within microseconds.
Would HFT traders flip a stock 10 times among each other just to fulfill a single Redditor's buy order? (Honest question, I don't know enough about standard HFT practices to confidently guess.)
https://www.bloomberg.com/opinion/articles/2021-01-29/reddit...