I'm not worrying until the Dow drops below 20K. A year ago it was 22K. Year to date, we're still up.
One interesting point. Trump is a little wacko today. He's attacking the Fed on the interest rise, and I think that couldn't have come soon enough. It should have slowly been happening over the last five years at least, to slowly move us out of Obama's crazy time. An artificial 2% home loan is nearly as crazy as the 16% I paid on my first Mortgage.
Mortgage loans in the 5-7% range would be normal and healthy, because that also lets people (retirees, etc.) afraid of the equities market to make something more than 0.05% in a savings account, and/or make something reasonable on a T-bill or CD. It might help stabilize crazy home prices as well.