Here's your 10-point cheat-sheet to this big story: 1. Merck & Co shares posted their biggest gain in 12 years after the company’s experimental pill slashed the risk of getting seriously ill or dying from Covid-19 in a study, findings that could eventually yield a simple way to treat many virus patients before they ever reach the hospital.
The US pharmaceutical company rose as much as 12% in New York trading, its biggest intraday gain since March 13, 2009. 2. The Dow and the S&P 500 oscillated between gains and losses on Friday, as investors weighed a warning from Fitch over the United States' debt ceiling against drugmaker Merck's progress in developing an oral COVID-19 drug.