Shares of social media firms fell sharply on Friday after Twitter Inc and Snapchat’s owner signaled advertisers had tightened their purse strings in response to a darkening economic outlook.

Pinterest Inc plunged 11.3%, Facebook-owner Meta Platforms Inc dropped 5.6%, Google-owner Alphabet Inc, which also sells ads online, fell 3.3%.

At current prices Pinterest, Meta, Twitter, Alphabet and Snap were collectively set to lose about $42 billion in market value.

Twitter also blamed its ongoing battle to close its $44-billion acquisition by Elon Musk for the surprise fall in quarterly revenue. The micro-blogging site’s shares were down 0.1% in choppy trading.

Advertisers have pared back spending amid rising interest rates and surging inflation as some of them struggle with labor shortages and supply chain disruptions, Snap Inc said on Thursday.

“If you want proof that companies are nervous about the economic outlook, just look at how media platforms and marketing agencies are bemoaning a tougher advertising market,” Russ Mould, AJ Bell investment director, said.

Investors are bracing for the slowest global revenue growth in the history of the social media sector as Apple Inc’s privacy changes further cloud outlook.

Snap Inc’s shares were down 36.4% and were the most heavily traded across U.S. exchanges, as the company said it was looking for new sources of revenue to grow.

“Unfortunately for Snap and the digital ad sector, we believe there are signs of further ad spending cuts,” RBC Capital Markets said in a note.

Attention now turns to quarterly reports from mega-cap firms Meta and Alphabet next week. Some analysts believe the drop in their share prices reflects what is likely to be a subdued report.

“While more revenue cuts for advertising stocks are likely, we think Alphabet has more relative revenue stability given breadth of advertisers, more expense flexibility than most peers,” analysts at Bank of American Global Research said.