Facebook's stock continued to slide south late last week, hitting an all-time low of $18.02 a share on Nasdaq.

Brokerages in New York dealt the dominant social network yet another blow by saying that the availability of more than one billion shares on the market would have a negative impact on the company.

In the first sale of shares on 16 August, Facebook's stock tumbled 7 per cent as the first lock-out period ended for inside investors, thereby allowing them to offload millions of shares.

As noted by Bloomberg Businessweek, shares in Facebook are expected to tank even further over the next six months as further lock-out restrictions expire in the autumn.

Shareholders cashing in their chips could hammer Facebook's already halved-in-value stock.

BMO Capital Markets analyst Daniel Salmon told Bloomberg that some advertisers had also lost their faith in Facebook's ability to flog their brands successfully via the network.

That viewpoint led Salmon to lower Facebook's stock price target to $15 from $25, which probably helped shares slip to a new low after close of play on Friday. When the company floated on 18 May on Wall Street its shares were initially priced at $38 a pop.

Late last month, one of Facebook's earliest investors sold about $400m worth of shares in the company. PayPal co-founder and Facebook director Peter Thiel and his venture capital firm, Founders Fund, cashed out most of his stock (about 20 million shares) in the social network, which claims to have roughly 1 billion users on its books. ®