Dow drops more than 600 points, suffers worst week since October

US markets declined yesterday, registering its biggest weekly fall since October, as investors gauged the ramifications of Johnson & Johnson's COVID-19 vaccine trial results.   So, the Dow Jones Industrial Average fell 621 points, or 2 per cent, to 29,983. The S&P 500 lost 73 points, or 1.9 per cent, to 3,714. And the Nasdaq Composite dropped 266 points, or 2 per cent, to 13,071. All three main indexes suffered their biggest weekly fall since the end of October, as the D...