Shares of technology companies fell slightly as initial ebullience about vaccine developments wore off.

At the Senate Judiciary Committee hearing conducted via videostream, Facebook's Mark Zuckerberg and Twitter's Jack Dorsey touted improvements their companies made in blocking or reducing misleading information in the 2020 election. Mr. Zuckerberg said Facebook was willing to work with legislators on regulations addressing the spread of misinformation online and other issues.

Tesla shares rallied, and Chief Executive Elon Musk looked set to become the world's third wealthiest person, after S&P Dow Jones Indices said it would add the electric-car maker's stock to the S&P 500 index, the widely followed broad-market benchmark.

"Tesla jumped, so that gives me confidence that growth [sectors] is still in demand," said Joshua Calloway, an independent options trader in Chicago.

Amazon.com rose after the online megastore said customers can buy prescription medications through a new store on its platform, a move that expands the e-commerce giant's presence in health care and further encroaches on the turf of traditional retailers.

Write to Rob Curran at rob.curran@dowjones.com

(END) Dow Jones Newswires

11-17-20 1653ET