America’s three major stock markets, the Dow, Nasdaq, and S&P, are all down sharply in morning trading as of this writing. The wave of red across investors’ monitors is primarily due to one major factor: uncertainty around how far the Iran conflict will travel and how long it will last. Here’s what you need to know about how markets are reacting. What happened? Over the weekend, President Donald Trump ordered strikes on Iran, during which the country’s supreme leader, Ayatollah A...