Dow Dives as Recession Fears Mount, Euro Slumps

Markets entered the second half of the year Tuesday with an opening sell-off that saw the Dow Jones Industrial Average shed more than 500 points by mid-morning.

That dashed hopes that the rally at the end of last week might signal a turn in investors’ fortunes following a first half that had market benchmarks suffering their worst returns in decades.

Adding fuel to the fire was news out of Europe that the euro has slid to a 20-year low against the dollar, almost reaching parity as global traders seek the...