The Dow Jones Industrial Average sank nearly 1,200 points Thursday, deepening a weeklong global market rout caused by worries that the coronavirus outbreak will wreak havoc on the global economy. Bond prices soared again, sending the yield on the 10-year Treasury to another record low. When yields fall it’s a sign that investors are feeling less confident about the strength of the economy going forward. “People can demand things that feel safe for irrational amounts of time,” said Katy Kaminski, chief research strategist at AlphaSimplex Group.