After-hours movers: Worthington Steel, Karman, MillerKnoll lead action

In after-hours trading on U.S. markets, Worthington Steel, Karman Holdings and MillerKnoll were among the most notable movers. Worthington outperformed on stronger-than-expected quarterly results, Karman rose after acquisition and guidance updates, while MillerKnoll slid following a revenue shortfall that disappointed investors.

Worthington Steel Inc. (NYSE: WS) reported a quarterly earnings and revenue beat that triggered a pronounced aftermarket rally, according to financial reports. Karman Holdings Inc. (NYSE: KRMN) announced acquisitions and raised its FY guidance, news that lifted the stock in extended trading. MillerKnoll Inc. (NASDAQ: MLKN) posted revenue below analyst estimates, prompting a sharp after-hours decline as markets reacted to topline weakness.

The immediate market response was visible in significant percentage moves for the affected names: Worthington recorded a strong post-close uptick tied to the earnings beat, Karman showed gains consistent with its strategic deals and upgraded targets, and MillerKnoll experienced a sizable drop tied to the revenue miss. These moves reflected sector-specific sentiment—industrial and steel-related cycles for Worthington, defense and aerospace consolidation for Karman, and demand sensitivity in commercial furniture for MillerKnoll.

In the broader economic context, steel manufacturers remain sensitive to end-market demand, inventory cycles and raw-material price swings, while defense suppliers are influenced by contract flows and government spending priorities. The office furniture segment is tracking commercial real estate and corporate realignment trends; all of these macro and sector forces shape how investors interpret quarterly results and guidance changes.

Analysts say near-term performance will hinge on integration success for Karman’s deals, Worthington’s ability to sustain margin improvements amid cyclical pressures, and MillerKnoll’s capacity to stabilize revenues and update guidance. Market participants will watch upcoming earnings calls and any management commentary for signs of durable demand or margin risk before repositioning portfolios.