Shares in the Dallas-based airline extended losses in aftermarket trading after Southwest declined to update its full-year profit guidance of at least $4 a share, underscoring the volatility in the industry. 

It said achieving those results would require lower fuel prices mixed with stronger revenue performance. It also projected second-quarter adjusted EPS in a range of 35 cents to 65 cents, with analysts expecting 59 cents.  

Southwest fell 3.8% and closed at $39.35 in regular trading Wednesday, mirroring stock declines of other carriers. 

Southwest’s decision is broadly in line with other carriers contending with fuel costs driven higher by the US-Iran war. Rival carrier Delta Air Lines Inc. has declined to update its full-year forecast, while others such as United Airlines Holdings Inc. and Alaska Air Group Inc. have revised or withdrawn guidance. 

For the first quarter, Southwest reported earnings of 45 cents per share, compared to analyst estimates of 46 cents. Operating revenue was $7.25 billion, compared with the roughly $7.29 billion analysts polled by Bloomberg expected on average.

Analysts are likely to press Southwest executives on an earnings call Thursday about the degree to which the carrier can boost fares to offset fuel prices without alienating customers. 

The airline is also in the middle of a major corporate makeover that includes adding premium seating, lounges and other initiatives designed to improve its finances.

“Much of the transformation Southwest has implemented, from premium seating to baggage fees, has been focused on improving revenue per existing core passenger,” Melius Research analyst Conor Cunningham said in a note. “With two domestic fare increases now in place, Southwest may be the most exposed to demand destruction among its peers.”

The Fortune 500 Innovation Forum will convene Fortune 500 executives, U.S. policy officials, top founders, and thought leaders to help define what’s next for the American economy, Nov. 16-17 in Detroit. Apply here.