Solar stocks are on track to close out the week with steep losses as Wall Street assesses last-minute changes slipped into the tax-and-spending bill approved by the House this week.  Bottom line: The bill is a threat to the industry.

U.S. stock index futures turned lower on Friday as shares of Apple dropped after U.S. President Donald Trump said the company would have to pay a 25% tariff if phones sold in the country are not made ...