Biden says US will impose “substantial costs” on adversaries who engage in cyberattacks; Trump has yet to personally comment about the SolarWinds hack (Christina Wilkie/CNBC)

Coinbase says it has confidentially filed for an IPO  —  Cryptocurrency giant Coinbase announced on Thursday that is has confidentially filed for a public offering, becoming the latest in a parade of high-profile startups to pursue an IPO in 2020.  —  Founded in 2012 as a simple way for consumers …