Shares in Facebook Tuesday fell below $30 US for the first time in their short trading history of eight days.

The stock closed down down $3.07, or 9.62 per cent, at $28.84.

That’s down 24 per cent from their initial trading price of $38 when its first public shares were offered on the markets on May 18.

Options in the social network’s shares began trading today, allowing speculators to place bets on whether the stock will drop or head higher. The options allow traders to speculate on a range of possible prices, from as low as $16, to as high as $49.

Analysts’ estimate for the share price range from under $14 to as high as $48.

The drop in share value has triggered several class-action lawsuits, as well as investigations by regulatory agencies.

The actions focus on allegations that one of analysts for Morgan Stanley, the lead underwriter of the share issue, held discussions with investors in which the analyst lowered his expectations for Facebook's revenues this year.

Securities law prohibits employees of the firms underwriting an IPO from selectively disclosing information to investors.