AAON Inc. shares plummeted 5.08% during intraday trading on Monday, reversing sharp pre-market gains after the company reported record second-quarter revenue and raised its full-year sales outlook, but lowered its gross margin forecast due to persistent scaling costs.

The stock had initially surged as much as 7.6% in pre-market trading after AAON reported net sales of $627 million, more than double the year-ago figure and well above analyst estimates of $491.5 million. However, the rally quickly fizzled as investors focused on the company’s reduced gross margin guidance for 2026, which now stands at 25%-26%, down from the prior 27%-28% range. The revision reflects ongoing pressures from capacity ramps, outsourcing, inflation, and price-cost timing, particularly at the AAON Coil Products segment.

While AAON raised its annual sales growth forecast to 55%-60% from 40%-45%, the lower profitability outlook signaled that the near-term costs of expansion are lingering longer than expected. The combination of robust demand and weakening margin metrics triggered a sell-off, with the stock falling more than 5% shortly after the opening bell.