Their actions meet the definition nearly exactly. The only difference is that Robinhood didn't directly execute the trades. However, the party making the trade doesn't matter. If insider information was used to benefit someone else, it is still illegal. And this case, it is clear that Robinhood acted in close coordination with 3rd parties to benefit themselves and their friends. The actions they took and the order they took them could not have occurred without Robinhood sharing insider info.