The export of American computer chips to China is a billion-dollar business from which the U.S. government itself is now ...

President Donald Trump’s move to extract a 15% sales tax from Nvidia Corp. on certain semiconductors sold in China did nothing to damp investor enthusiasm for the world’s most valuable company.

The tech sector is no stranger to market-leading gains. Over the past eight years, it’s finished first or second among the S&P 500’s 11 sectors five times. Since the conclusion of the last bear market ...