Samsung shares lost more than $10 billion in market value, following a US jury's finding that the company illegally copied Apple products.
The company's share price dropped by seven percent, the biggest one-day fall in four years, after it was ordered to pay $1.05 billion in damages to Apple.
The damages were higher than expected - and there's a distinct possibility that Apple wil succeed in winning an injunction against the sale of Samsung products in the US at a court hearing scheduled for 20 September. Indeed, it may attempt to impose a ban on the Galaxy S3, which wasn't covered in the trial.
There are certain question marks over the decision reached by the jury - the figure for damages was reduced with alacrity when it was realized that the math didn't quite add up. The speed with which the verdict was reached has also rung alarm bells for some.
Samsung says it plans to appeal.
"It is unfortunate that patent law can be manipulated to give one company a monopoly over rectangles with rounded corners, or technology that is being improved every day by Samsung and other companies," it says.
"This is not the final word in this case or in battles being waged in courts and tribunals around the world."
Apple hasn't been so successful in its claims against Samsung elsewhere. Recently, a British court dismissed its copyright claims in the UK, and last week a South Korean court ruled that both companies had copied each other.
Today, according to reports, both companies have been ordered to pull products from the shelves, including Apple's iPhone 3GS, iPhone 4 and the first and second generations of iPad tablets, along with the Samsung Galaxy S, SII, Galaxy Tab or Galaxy Tab 10.1.