Many retail investors see payment for order flow as just another example of companies selling consumer data.
US stocks ended Wednesday mostly lower. Robinhood stock soared as the popular trading app notched a strong two-day gain.
Robinhood hit an intra-day high of $85 on Wednesday, just 19% below the $101.50 stock price needed for Tenev and Bhatt to unlock their equity award.
Most of Robinhood's mentions on the forum were positive, with one user saying, "unpopular opinion: Robinhood still has the best mobile interface."
Robinhood experienced a choppy debut last week, with shares falling as much as 12% from its IPO price of $38 per share.
Last month, 12,602 of Robinhood customers bought Duolingo at its IPO price, while 78,250 customers participated in the F45 Training IPO.
This year's debuts of Coinbase and Didi Global pulled in more money from individual investors than Robinhood's hot-anticipated IPO.
The online trading app priced its IPO late Wednesday night at $38 per share, giving it a valuation of $32 billion.
The pricing comes at the bottom end of the range set by Robinhood during its investor roadshow this month.
In April, Robinhood reduced the annual salary of Tenev and Bhatt to $34,248, which was the 2019 median wage of US workers.