Over the past year, Apple (AAPL 0.04%) and Amgen (AMGN -0.69%), two well-established companies that are part of the iconic Dow Jones Industrial Average, have faced significant headwinds. Apple is struggling due to the threat that President Donald Trump's trade agenda poses to its business, while Amgen faced a clinical setback late last year. Apple and Amgen have lagged the market over the trailing-12-month period, but despite their issues, both stocks are worth investing in for the long haul. Here's why. An ...