Weibo's stock fell 5.48% in pre-market trading on Wednesday, following the release of its fourth-quarter financial results.

The social media company reported a net loss attributable to shareholders of $4.7 million for the quarter, compared to a net income of $8.9 million in the same period last year. Diluted net loss per share was $0.02, down from a profit of $0.04 per share a year ago. Non-GAAP net income also declined to $66.4 million from $106.6 million year-over-year.

Despite a 4% increase in net revenues to $473.3 million, profitability was pressured by a 13% rise in costs and expenses, primarily due to increased ad production cost and marketing expense. The company's operating margin contracted to 19% from 26% in the prior year period.