In 1990 a credible media person asked what turned out to be a trick question: How much money have all of the US airlines made together, all-time, since their inception around 1920?
The answer was that by 1990 they had collectively lost $4B.
Reminds me of this quote from Robert Crandall, the former CEO of American:
During the latter period of Crandall's tenure as CEO, investor concern over airline bankruptcies and falling stock prices caused Crandall to remind his employees about the dangers of investing in airline stocks. Known for his candor, Crandall later told an interviewer, "I've never invested in any airline. I'm an airline manager. I don't invest in airlines. And I always said to the employees of American, 'This is not an appropriate investment. It's a great place to work and it's a great company that does important work. But airlines are not an investment.'" Crandall noted that since the airline deregulation of the 1970s, some 150 airlines had gone out of business. "A lot of people came into the airline business. Most of them promptly exited, minus their money," he said.