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.

Technology: Scott Kessler, deputy global director of equity and industry research at CFRA, sees a Trump presidency as having a neutral impact on the technology sector. "We think a Donald Trump presidency coupled with a Republican-controlled Congress makes his proposal for a 'repatriation of corporate profits held offshore at a one-time tax rate of 10%' as much more likely," he said. "We see many large U.S. IT firms potentially benefiting, with increasing domestic growth investment, stock buybacks, and dividend payouts."

However, Kessler also notes that Trump's hard stances related to trade could negatively impact the sector, which in 2015 generated a higher percentage of non-U.S. revenues than all but the energy sector (58% for IT vs. 44% for S&P 500).

For his part, Johnson said many tech firms are sitting on enormous cash piles. "Much of the M&A will likely happen in the technology sector as tech firms put that cash to use in a more friendly M&A environment," he said.

Financials: According to Erik Oja, an equity analyst with CRFA, investors in bank stocks should focus on three things when trying to determine what the future will bring for banks.

Yes, there will be negative short-term effects on global currencies and interest rates;

However, the Dodd-Frank Financial Reform legislation may be loosened up a bit, which would be a positive.

Economic growth may benefit from defense spending and fossil-fuel energy production, a positive for bank lending.

As of this week, CRFA Research had four-star ratings on Bank of America (BAC) - Get Report , JPMorgan Chase & Co. (JPM) - Get Report and Wells Fargo (WFC) - Get Report and an overweight recommendation on Financial Select Sector SPDR Fund (XLF) - Get Report .

Energy: A Trump presidency will be a negative for the solar industry, according to Angelo Zino, an equity analyst with CFRA Research. "The U.S. solar industry has prospered over the last eight years, with our forecast of annual installations substantially increasing from a run rate of less than 500 megawatts in '08 to more than 13 gigawatts in '16," Zino wrote in a report this week. "We believe a Trump presidency along with a Republican-led Congress poses significant risks to a potential reduction/elimination of the 30% ITC, extended at the end of '15. While we have had a negative tilt on solar, and see peak U.S. demand in '16, we think the election outcome adds uncertainty."

CFRA has "sell" opinions on JinkoSolar (JKS) - Get Report and SolarEdge (SEDG) - Get Report . CRFA also cut its opinion on share of Sunpower Corp. (SPWR) - Get Report to hold from buy.

Meanwhile, traditional energy sources will benefit from a Trump presidency, said Johnson.

For his part, Stewart Glickman, an analyst with CFRA Research, raised its opinion Valero Energy (VLP) to buy from hold. "We think the surprise Trump win in Tuesday night's U.S. Presidential election could usher in a more favorable regulatory climate for refiners, particularly in regard to renewable fuel obligations, which have been onerous of late," he wrote. "The dividend yields 4% and we estimate a superior free cash flow yield as well, which could lead to dividend hikes."

In addition, Glickman maintained the firm's "buy" opinion on shares of Noble Energy (NBL) - Get Report .

Health care: In June, Jeffrey Loo, an analyst with CFRA Research, noted that a Trump presidency, uncertainty and volatility would increase for the health care sector and investors. That's because Trump pledged to repeal and replace the Affordable Care Act (ACA) on day one, which Loo viewed as highly disruptive to the sector, particularly to health care facilities, health care services and managed health care.

At the time, Loo noted that if Republicans do not have a 60-seat super majority in the Senate (which they do not), Democrats could utilize a filibuster to prevent a vote to repeal the ACA. On the other hand, Loo noted that Republicans may resort to the "nuclear option," which entails the presiding officer to rule that a simple majority vote is sufficient to end debate and bring legislation to a vote. Based on recent partisan politics, Loo wrote at the time there is a decent possibility Republicans may resort to this option.

Given that, CRFA Research this week lowered its opinion on shares of Tenet Healthcare (THC) - Get Report to hold from buy. "Although Republicans did not obtain a 60-person super majority in the Senate and our belief Democrats will use a filibuster to try to stop drastic changes to the ACA, we believe several ACA-related benefits could end," Loo said. "We believe Republicans will try to end the Medicaid expansion and the individual mandate, which will raise THC's uncompensated care rates and adversely impact profitability."

CFRA Research also lowered its opinion on shares of Molina Healthcare (MOH) - Get Report and Centene (CNC) - Get Report to hold from buy. "We believe Republicans will try to end the Medicaid expansion which has been the main growth driver for MOH and CNC," Loo wrote. "We also see a much lower appetite for acquisitions now."

CFRA Research maintained its "hold" opinion on shares of Community Health Systems (CYH) - Get Report . The reason: "We believe Republicans will try to end the Medicaid expansion and the individual mandate, which will raise CYH's uncompensated care rates," Loo wrote.

Cement manufacturers: "If you take Trump at his word, it is going to take a lot of cement to build that wall on the southern border," said Johnson.

Other sectors to consider: "Private prison firms will likely benefit from a crackdown on illegal immigration," said Johnson.