Online discount site Groupon is reported to be planning a flotation, while Facebook is rumoured to be delaying its IPO until the end of 2012.
The online coupon site is aiming to go public in late October or early November, reported the New York Times.
Facebook surpassed 500 shareholders in January when Goldman Sachs became an investor, meaning it will have to publish numbers by April 2012. Many have speculated that once its financials are disclosed the company will float.
But sources told the Financial Times that the date has been pushed back from April until September to keep employees focused on product developments in the pipeline.
The social network company has attracted a $66.5bn (£42.1bn) valuation from trading on secondary markets, according to the newspaper.
Linkedin was the first social media company to float in January, trading its first shares in May.