Robinhood launched limited IPO trading earlier this year where it would offer allocations of select public offerings to investors. Included in this was shares of the company’s own stock. Rules put in place to prevent users from day trading IPOs are providing a lesson to investors.

What Happened: The highly anticipated IPO of Robinhood Markets HOOD opened for trading Thursday at $38 and closed its first day of trading at $34.82.

Some users on Twitter were surprised to get a warning when trying to sell the Robinhood shares the day after the IPO; they received an “IPO flipping warning.” The warning said a sale of the stock before the 30-day waiting period would result in a restriction from IPO trading for 60 days.

Robinhood is not the first company to put rules in place like this.

The IPO Flipping Rules: Robinhood offered IPO shares in FIGS Inc FIGS 0.28% as its first pre-IPO allocation for users.

Robinhood says on its website it would discourage flipping by refusing allocations in IPO shares in the future for customers. The policy applies to all IPOs offered on Robinhood’s IPO Access, not just Robinhood shares.

SoFi Technologies SOFI 1.03% began offering IPO allocations to customers earlier this year. The company put in place rules to discourage “flipping.” A customer selling a stock within the first 30 days post-IPO faces limits on future IPO allocations including up to a 180-day sit-out period. Multiple violations could lead to suspension from the IPO platform.

SoFi also listed rules to charge a $50 fee for the sale of IPO shares in the first 120 days post-IPO.

HOOD Price Action: Shares of Robinhood were up 4% to $36.12 on Friday.