FormFactor (FORM) shares tumbled 5.10% in after-hours trading on Thursday, despite the company reporting better-than-expected third-quarter results earlier in the day. The semiconductor testing equipment maker's stock had initially surged 18.3% following the earnings release, but the enthusiasm appears to have waned by the end of the regular trading session.

The after-hours decline comes as TD Cowen maintained its Hold rating on FormFactor stock. This cautious stance from analysts may have disappointed investors who were hoping for a more bullish outlook following the strong quarterly performance. The contrast between the initial positive reaction and the subsequent decline suggests that market participants are reassessing the company's long-term prospects in light of the broader semiconductor industry landscape.

While FormFactor's Q3 results exceeded expectations, the maintained Hold rating and the stock's sharp reversal indicate that concerns about future growth or industry headwinds may be overshadowing the recent financial performance. Investors will likely be closely watching for any additional analyst commentary or company guidance to better understand the factors driving this after-hours sell-off.