Facebook shares have fallen nearly six per cent on opening, leading the markets lower in starting trade also hit by poor earnings from Dow Chemical.
Six minutes into trade on Thursday, the Dow Jones Industrial Average was down 27.41 points, or 0.2 per cent, to 13,883.01.
The broad-based SP 500 dropped 9.5 points, or 0.63 per cent, to 1,498.34.
The tech-heavy Nasdaq Composite fell 2.05 points, or 0.07 per cent, to 3,140.26.
The drop in shares came as social networking giant Facebook reported a big fall in year-over-year earnings and signalled higher costs as it invests in data centres.
Dow and UPS also came in with weak results, each reporting quarterly losses.
The results followed Wednesday's US economic report that showed the economy contracted by 0.1 per cent in the fourth quarter last year.
