The US markets closed mixed on Tuesday as tech stocks were pulled lower by continuing economic recovery attracting investors out of growth stocks. Zoom tanked 14.7% on Tuesday after the pandemic winning stock released third quarter results. Dell Technologies rallied after hours following the release of third quarter results as demand for PCs continues to surge. Fully autonomous boats called ?Roboats? are being tested in Amsterdam to transport people, gather waste and link together to form a bridge or other infrastructure.