Stocks making the biggest moves after hours: Tesla, IBM, ServiceNow

After-hours trading featured notable moves in Tesla, IBM, ServiceNow and Southwest Airlines, with company results and guidance driving price swings. Investors reacted quickly to mixed quarterly figures, revenue and earnings beats that carried caveats, and operational or clinical updates that changed short-term sentiment.

Tesla slipped in extended trading after a mixed quarterly report where revenue beat but margin and some profitability metrics disappointed, prompting short-term selling pressure; Investing.com recorded about a 1.4% post-close decline. IBM reported results that beat estimates but tempered growth expectations—projecting more modest constant‑currency revenue growth—leading to after-hours selling despite the beat. ServiceNow moved sharply on its quarterly details and guidance, while Southwest surprised with a profit that pushed the stock higher in after-hours trade.

These after-hours moves underscore how earnings season can amplify volatility: post‑close reactions often translate into heightened opening volatility the next trading day as institutions and retail traders reprice exposure. Short-term market impact is typically concentrated in sector peers—tech names may reprice around AI and software spending signals, while airline stocks react to demand and cost trends.

In a broader context, trends such as corporate IT spending, AI-related investment cycles and travel demand recovery frame the reactions of these names. IBM’s more cautious outlook and ServiceNow’s performance feed into a wider reassessment of growth trajectories in enterprise software, while Southwest’s surprise profitability points to operational resilience in pockets of the travel sector. Macro data and central bank policy will continue to set the backdrop for how persistent these moves prove.

Analysts say the immediate focus will be on management commentary, margin trajectories and guidance updates that follow earnings releases; these elements will determine whether after-hours swings mean a brief repricing or the start of a longer trend. Market participants should therefore monitor pre‑market activity and analyst note flow ahead of the next session and adjust risk sizing accordingly.