Tesla's launch of its futuristic Cybertruck pickup suffered a setback when its "armored glass" windows shattered, leaving a flustered Elon Musk to flounder through the rest of his presentation in front of a badly damaged vehicle. But it was the overall look of the electric vehicle that worried Wall Street on Friday, driving the automaker's shares down six percent.

Musk unveiled the all-electric battery-powered Tesla Cybertruck in California on Thursday. But the demonstration of the vehicle's indestructible windows didn't appear to go entirely to plan after one assistant threw a steel ball bearing at the truck only to see the armored glass smash.

Musk singled out the Ford F-150, the top-selling vehicle in the United States, to highlight the capabilities of the Cybertruck, showing an edited video of the two trucks in a back-to-back "tug-of-war" in which the Tesla truck wins.

Some Wall Street analysts praised the launch on Friday, but others doubted the futuristic design's mass appeal. Tesla shares were down six percent at 333.41 U.S. dollars.

Shares of Ford and General Motors rose about two percent. General Motors' first electric pickup will go on sale in 2021, around the same time as Tesla's.

The U.S. pickup truck market is one of the world's most profitable vehicle segments and is dominated by Ford, General Motors and Fiat Chrysler Automobiles.

Friday's selloff dented a 40 percent rally in Tesla's shares that was sparked after Musk reported an unexpected quarterly profit on October 23. That stock surge scalded traders betting Tesla will fail to survive an eventual wave of electric vehicles made by more established automakers.

But even after traders recently cut their short bets against Tesla to 22 percent of its float from over 30 percent in August, its stock remains one of the most shorted on Wall Street, according to S3 Partners, a financial analytics firm. That level of short interest underscores widespread skepticism about Tesla's path to long-term profitability.

(With input from AFP, Reuters)