Amazon-backed EV maker Rivian sold shares in its initial public offering (IPO) at $78 per share, above its target range, to raise over $10 billion, people familiar with the matter said on Tuesday. The IPO gives Rivian a valuation of about $66.5 billion. The raise was the one of the largest ever for an IPO in the U.S., according to data from Dealogic. On a fully diluted basis, Rivian will be valued at over $77 billion. Rivian priced 135 million shares at $78 per share, the sources said, requesting anonymity as the talks are confidential. On Friday, Rivian had boosted its price range to $72 to $74 per share, up from an earlier range of $57 to $62 a share. Rivian did not immediately respond to a request for comment. (Reporting by Echo Wang in New York and Anirban Sen in Bengaluru Editing by Chris Reese)