Roku Craters on Weak Outlook, Adding to Advertising Worries

Roku Inc. slumped 25% in late trading after saying advertisers are pulling back on spending due to economic concerns, adding to jitters about the slowing growth of marketing spending.

Shares of the maker of streaming-TV devices fell to $63.35 in late trading after the company reported disappointing second-quarter results. The stock had already declined 63% this year as enthusiasm ebbed on Wall Street for the online video industry.