A selloff in stocks and bonds was trimmed as assurances on American action to secure shipping lanes through the Strait of Hormuz amid the Iran war pared what had been an over 9% surge in oil. Following an earlier slide in the S&P 500 that reached 2.5%, the equity benchmark dropped less than 1%. President Donald Trump said the US will escort and insure tankers and other vessels through the world's most-critical energy chokepoint. Oil prices waned in post-settlement trading, with Brent trading near $80 a barrel. Don Calcagni, Chief Investment Officer at Mercer Advisors, joins Bloomberg Businessweek Daily to discuss. Calcagni also speaks about investment strategy amid a volatile backdrop. He speaks with Carol Massar and Tim Stenovec from the Bloomberg Invest conference in New York City.