Markets and investors might not like uncertainty.

So, how's this for a dose of certainty.

Under a President Donald Trump some sectors are likely to do well and others not so much. But where are the opportunities and where are the risks? To find out, we asked experts who participated in TheStreet's Retirement Advisor panel discussion in September for their views. Here's what we found:

So, the first order of business might be this: Do nothing. "I believe the best course of action for most investors is to do absolutely nothing differently," said Robert Johnson, president and CEO of the American College of Financial Services. "If you had a retirement plan on Tuesday before the election results were announced, stick to it."

Yes, many investors won't be able to restrain themselves and will want to de-risk their portfolios, Johnson said. "The problem with trading in and out of the market is that you must make a series of good decisions - when to get out and when to get in again," he said. "That is why the vast majority of active investors underperform buy and hold."

Still, Johnson and others said there are pockets of opportunity and risk in the following sectors: consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology, materials, telecommunication services and utilities

Mergers and acquisitions: "I think there is a backlog of mergers and acquisitions due to the uncertainty on whether they would be allowed," said Johnson. "For instance, recently a proposed Office Depot/Staples merger was blocked. Both firms are struggling and it makes little sense to block it. The climate will be more conducive to M&A with a Trump presidency." More M&A activity, said Johnson, will benefit investment banking firms.

If you liked this article you might like

With the Fed, It's Different This Time

How to Get Rich Using Warren Buffett's Favorite Stock Market Indicators

How to Live Just Like Billionaire Warren Buffett

Why Hurricanes Won't Force the Fed to Ditch a December Rate Hike

How to Make a Deal Like Billionaire Investor Warren Buffett