It is probably freely invented, because it sounds good and gives clicks.
Here is a recent articel from FORBES, where they write about Barclay research that looked into exactly that: "are retail Robinhood investors moving the markets?": https://www.forbes.com/sites/sergeiklebnikov/2020/06/12/no-the-market-is-not-rallying-because-of-robinhood-traders-barclays-says/#1b19cce33fbb
It concludes that in the contrary, they stick out for in average worse market timing than other investors, and for losing more than they are gaining by mis-timing the markets.
It also shows that their impact by volume is negligible.
[my markups in bold:]
No, The Market Is Not Rallying Because Of Robinhood Traders, Barclays
The research “casts doubt on the idea that retail holdings are the
cause of market returns,” according to Barclays analyst Ryan Preclaw.
The idea that new investors using zero-cost brokerage firms like
Robinhood were driving up the market has become a popular narrative on
Wall Street. “Since March 2020 we have seen the opposite of the
conventional wisdom—all else equal, more Robinhood customers moving
into a stock has corresponded to lower returns, rather than higher,”
Barclays’ analysis found that for all the Robinhood
investors cashing in on the stock market’s rebound over the past few
months, just as many are getting it wrong and losing money: Overall,
Robinhood traders’ top picks are underperforming