(Bloomberg) -- Twitter Inc. tumbled as much as 9.1% on Wednesday, the biggest drop in six months, after the social-media company’s third-quarter revenue and fourth-quarter sales outlook trailed Wall Street projections.

The stock is down for a sixth day, marking its longest streak of declines since August. The shares have come under pressure in recent sessions following results from social-media peers Snap Inc. and Facebook Inc., both of which highlighted headwinds from Apple Inc.’s new limits on consumer data collection.

Twitter’s slump signals that its quarterly report wasn’t enough to assuage investor concerns about the potential impact of Apple’s privacy tracking changes, even as Twitter downplayed the effect. Some analysts have previously noted that the company is less exposed to Apple’s changes than some ad-dependent peers because Twitter relies more on brand advertising than direct response ads.

The shares reflect “underlying concerns that growth and/or guidance would not escape the headwinds caused by Apple IDFA deprecation and supply chain challenges,” Baird analyst Colin Sebastian wrote in a research note, referring to changes around Apple’s data-collection policies.

Investors may also be disappointed with U.S. user results that were flat quarter over quarter, Jefferies analyst Brent Thill said, adding that the lackluster growth may raise concerns about U.S. market saturation.

Social-media peer Pinterest Inc. followed Twitter lower on Wednesday, falling as much as 4.3% to extend a recent slump. The company is scheduled to report third-quarter results on Nov. 4. Snap also traded lower, down as much as 6.3%. Elsewhere, Facebook is down 0.1%.

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