Boeing is trading 4.47% down at $189.21 following reports that Southwest and United will not accept new 737 MAX jets with software under FAA review. - Boeing said the glitch could affect automated guidance during certain landing procedures and is developing a permanent software update. - The FAA is assessing the issue and will act if it identifies a safety concern. - Broader markets are weaker, though supplied index declines below 0.5% do not establish a broad-market driver.