Investors should “aggressively buy” Boeing shares as the stock’s recent slump already reflects the grounding of the 737 Max jets and a possible reset of 2019 guidance, Robert W. Baird analyst Peter Arment wrote in a note to clients on Tuesday.

“We believe the risk/reward is very compelling on the Boeing stock at current levels,” Arment said. He recommended that both short- and long-term investors aggressively buy shares.

Boeing shares (BA) rose as much as 1.4 percent in New York. The shares had slumped 12 percent since the Ethiopian Airlines crash on March 10, before Tuesday’s gains.

Arment expects a software solution to the 737 Max within days and implementation to begin immediately for grounded aircraft and those awaiting delivery. He lowered his estimates for Boeing’s 2019 deliveries and results and now expects the company to deliver 871 aircraft during the year, 30 less than his prior view.

He also cut his earnings estimate for the year by 40 cents a share, to $19.85. The average analyst estimate is $20.14, according to data compiled by Bloomberg.