By Jonathan Stempel (Reuters) -A federal judge said Coinbase shareholders may pursue a narrowed lawsuit accusing the largest U.S. cryptocurrency exchange operator of concealing business risks, including whether it would be sued by the Securities and Exchange Commission. In a Tuesday night decision, U.S. District Judge Brian Martinotti in Newark, New Jersey rejected requests by Coinbase, top executives and directors for a full dismissal of claims based on dozens of statements made over two years in regula ...