Why the Dow is in such a historic funk and how concerned you should be [Video]

The Dow Jones Industrial Average has been declining for nine straight days, posting its longest losing streak since February 1978. What is going on and how concerned should investors be?

First off, let’s explain which stocks are driving the losses.

The biggest laggard in the 30-stock Dow during this losing streak has been UnitedHealth, which has contributed to more than half of the decline in the price-weighted average over the past eight sessions. The insurer has plunged 20% this month alone amid a broad sell-off in pharmacy benefit managers after President-elect Donald Trump‘s vow to “knock out” drug industry middlemen. UnitedHealth is also going through a tumultuous period with the fatal shooting of Brian Thompson, the CEO of its insurance unit.

And then there’s a rotation going on with investors selling out of the cyclical names in …