What a time it is to be a major automaker.

General Motors and Ford have just capped off the best year in the history of US auto sales. Together they control a third of the most competitive car market in the world and have been raking in profits as SUVs and pickup trucks stage a monumental comeback amid cheap gas prices.

The reward for this on Wall Street? Their shares have been hammered all week. 

Even though GM and Ford, along with fellow Detroit “Big Three” car maker Fiat Chrysler Automobiles, enjoyed a record sales year, they can’t seem to sell Wall Street a growth story. 

The companies are up against investors’ long memories: Cars are a cyclical business and the strong growth in sales will surely end when the economy begins to slow. That’s the fear at least, but it belies the fact that the auto industry could add another million vehicles in sales next year as more people get jobs and replace old vehicles (the average age of a car on US roads is 11 years.)

F GM Chart 1-6-2016Screenshot via Google Finance

It has dogged the companies for a while. GM and Ford were flat last year, and although FCA got some love that had more to do with the spinoff of Ferrari than anything else. 

This has been a source of dismay in Motown, and now – it seems – the managers in Detroit are trying to do something about it by trying to prove to Wall Street that they have a growth story that goes beyond excellent sales.

At the Consumer Electronics Show in Las Vegas this week for example, Ford and GM are pitching the technology angle hard. Everything from self-driving cars to in-vehicle infotainment systems is on display and executives from both companies are in attendance.

GM has even gone so far as to start investing in ride-on-demand service Lyft, whose explicit business plan involves people not buying cars.

CES 2016 fordSteve Kovach/Business InsiderFord CEO Mark Fields at CES last year.

It doesn’t seem fair that the US auto industry has recovered spectacularly over the past five years, becoming a high point in the economy, and that shares of Ford and GM and done nothing but lose value. 

Wall Street prefers companies in the automakers’ supply chains, mainly because it ultimately thinks the big car companies are all selling the same thing and will eventually compete away their profits in a world where no one will ever again command half the market, as GM did in the postwar period.

That could be true, but at least Ford and GM aren’t standing still.

We’re going to disrupt ourselves, and we are disrupting ourselves, so we’re not trying to preserve a model of yesterday,” GM CEO Mary Barra said in an interview last year.

The effort is there. But unfortunately, when it comes to Wall Street, the rewards may be slow to materialize.