Either one could win, but one win would benefit investors more.
Three possibilities spring to mind.
USAF gives Boeing the green light to begin production, but will KC-46 make Boeing's stock ticker glow green as well?
AeroVironment, GoPro, Elbit Systems, and Ambarella could benefit from surging demand for unmanned aerial vehicles.
A de facto merger will give Airbus control over its biggest space industry customer.
A few airlines are deferring orders with Airbus and Boeing. Meanwhile, Allegiant Travel just ordered new airplanes for the first time.
A plane that flies for months at a time could expand internet access across the globe.
American Airlines has deferred its Airbus A350 orders again, cutting its near-term international growth plans almost to zero.
Electric planes could be the next big thing.
Embraer didn't sell nearly as many planes as Boeing or Airbus at the Farnborough Airshow, but it still had a better week than either of its larger rivals.