Technology 45 mins ago But several signs are pointing to institutional investors as big drivers of the wild price action on the way up. "Although retail buying was portrayed as the main driver of the extreme price rally experienced by some stocks, the actual picture may be much more nuanced," JPMorgan global quantitative and derivatives strategy analyst Peng Cheng told clients in a note. JPMorgan's quant team uses public data from exchanges and applies a proprietary methodology to identify which flows are from retail traders. GameStop was number 15 on the firm's retail buying list for January. The rookie investor "vigilantes" grabbed the most attention by being all over social media, posting screenshots of their positions and crucifying Robinhood and other brokers when the firms were forced to limit trading in the high-flying names. The membership of Reddit group WallStreetBets has rocketed to 8.5 million subscribers.