Reddit's S-1 filing for its upcoming IPO revealed it will offer some shares through a directed share program for moderators and users. This is unusual for IPOs, which are usually bought primarily by institutional investors. The program could result in increased volatility in Reddit's stock price after the IPO, according to the filing. Participants in the program will not be subject to the typical post-IPO lock-up period that limits early selling. Reddit will invite eligible users based on their "karma" reputation score as measured by other users.