Investors bet on testing, treatments for restart of U.S. economy

(Reuters) - Investors are pinning their hopes for the reopening of the U.S. economy on the potential for wider availability of testing for COVID-19 cases and on drug trials for treatments of the deadly disease but said, until there is concrete progress in these areas, further stock market gains may be limited.Much of the S&P 500's almost 27% advance above its March 23 low has been due to hopes that massive U.S. fiscal and monetary support would dampen the economic blow from stay-at-home orders..