https://www.reuters.com/article/us-retail-trading-griffin/citadels-griffin-details-firms-role-in-trading-during-gamestop-rally-idUSKBN2AI01B

Electronic trading firm Citadel Securities last month played a critical role in processing retail investors' orders and was not involved in online trading app Robinhood's decision to limit trading in GameStop, Citadel's founder Kenneth Griffin said.