Shares of Boeing Co. /zigman2/quotes/208579720/composite BA -5.83% took a hit in afternoon trading Friday, after Southwest Airlines Co. /zigman2/quotes/201071949/composite LUV -4.64% disclosed in an SEC filing that it will be pushing back the expected return of the grounded 737 MAX planes by a month. Boeing's stock was down 1.5%; just before the release of Southwest's 10-Q filing with the Securities and Exchange Commission, the stock was down 1.0%. Boeing's stock price decline of $5.40 was shaving about 37 points off the Dow Jones Industrial Average's /zigman2/quotes/210598065/realtime DJIA -4.42% price, which was down 30 points. Southwest shares were down less than 0.1%. Southwest had said last month that it has removed the 737 MAX from its schedules through Feb. 8, 2020, as the air carrier estimates it will take two months to comply with applicable regulatory directives, including necessary training, once the Federal Aviation Administration lifts its order to ground the 737 MAX. "Based on continued uncertainty around the timing of the MAX return to service, the company soon plans to proactively remove the MAX from its flight schedule through March 6, 2020," Southwest stated in the 10-Q. Boeing's stock has gained 4.6% over the past three months and Southwest shares have rallied 15.3%, while the Dow has advanced 4.8%.