Geoffrey Yu, head of the UK investment office at UBS Wealth Management
Longer term, the main concern for markets is how the president approaches his task of “making America great again” – namely, will this be pursued at the cost of other countries?

Comments from President Trump that indicate his stance towards trading partners, particularly in Europe and China, and the conciliatory or punitive tone of those remarks, have the greatest potential to sway market sentiment.

We believe the dollar has already peaked. As an inauguration present to the new president, we expect the dollar will weaken from here against the euro, yen and sterling. But, against emerging markets it could remain highly idiosyncratic, with USD/MXN trading off the president’s tweets. Confusion will continue to reign supreme in markets, with contradictory statements on the value of a strong currency from the president and incoming treasury secretary Steven Mnuchin.

But, without a solid fiscal boost and no change to current levels of inflation, the Fed is likely to respond to the strong dollar eating into inflation and the downside risks this provokes. Ultimately, although there are many different drivers, we expect the Fed be the largest catalyst for currency moves in the coming months.

Ben Gutteridge, head of fund research at Brewin Dolphin
The surge in optimism surrounding Trump’s presidential election victory, at least in regard to stock market performance, centres on his economic platform.

There is a considerable weight of expectation on the Trump administration and it now must deliver on tax reform - cutting rates for both corporations and households. The clean sweep of Republican leadership in US Congress and the Whitehouse suggests such an aspiration is readily achievable. The apparent conflict between Trump and Republican House leader Paul Ryan over the implementation of a border adjustable tax has the potential to delay a grand bargain. However, on balance, we remain very optimistic.

Effective tax rates for larger US multinational companies are already very low due to their international revenue collection and the associated lower tax rates. To that end smaller US companies, whose earnings are generated to a far greater extent domestically, will enjoy a much bigger boost to after-tax profits. A nationwide roll-out of large scale infrastructure spending is a need anyone who has travelled to the US would support. This is not, however, a policy priority for the core Republican leadership. Execution is likely to be delayed in 2018 at the earliest, which may frustrate share prices for associated infrastructure equities.

Trump’s intention to expand government spending, when the economy is already running with an extremely low unemployment rate, is likely to trigger higher rates of wage inflation and boost growth. This could mean the US Federal Reserve raises interest rates faster than the market currently expects, which would be bad news for bonds. It is likely, however, that the associated dollar strength keeps a lid on US inflation, due to a lower cost of imports, meaning a "blood bath" in bonds is avoided. Government bonds look unlikely to make investors much return, if any, over the short to medium term, but remain a good hedge against a negative growth shock, such as a Chinese hard landing.

Bank of America Merrill Lynch
Our economics team sees a serious escalation of US-China trade tensions as the biggest risk to the global economy in 2017. At minimum we expect China to be declared a "currency manipulator" and for specific cases to be brought against China. Further escalation will depend on finding common ground and recognising the risks of aggressive actions.

Source, an ETF provider
The S&P 500 delivered an annualised return of 13.9 per cent under Barack Obama and 15.2 per cent under Bill Clinton, ranking their terms fifth and third respectively in terms of stock market gains . But with the S&P 500 currently on a Shiller Price-Earnings ratio of more than 28 it is unlikely that it will do better under President Trump. Since 1853, the best annualised returns by the US stock market were made under presidents Harding/Coolidge ; Hayes ; Clinton ; Lincoln ; and Obama .

Witold Bahrke, senior strategist at Nordea Asset Management
While the most popular so called “Trump-trades” – in essence long developed market equities and short government bonds – have lost some steam ahead of Trump’s inauguration, there is still breathtaking optimism on both Main Street and Wall Street. This is mainly fuelled by hopes of unprecedented fiscal stimulus outside recessionary episodes from the incoming US administration.

Equities are discounting a significant growth pick up without meaningful monetary tightening spoiling the show. Confidence among small and medium-sized companies in the US is at the highest level since 2004 and US company earnings estimates for this year were not revised down at the end of last year like they normally are.

However, scepticism is warranted, especially as some markets seem to be priced to perfection when it comes to the overall economic outcome for 2017.

Erik Nielsen, chief economist, UniCredit
Trump’s world is principle-free and transactional. Every interaction is a zero-sum game with a winner and a loser – and the US will win “like never before”. Good luck, trade negotiators from the rest of the world...

But America is a great and diverse country, with elaborate checks and balances on power. Yesterday, millions of Americans took to the streets in cities all across the country to register their disapproval of the incoming president. According to estimates by the police and the National Park Service, there were more people on the Mall in DC yesterday than during Friday’s inauguration – well, until suddenly the National Park Service stopped tweeting, and withdrew their earlier messages, reportedly because of instruction from the administration to stop providing such estimates. But while they can shut down public sector information , private news organisations and photo evidence continued to show clear evidence of the relative numbers.

While recent days have caused a lot of concerns, there are still two scenarios for the US: one, in which the Trump administration – recognizing the deep division of the country - heads for relatively traditional policies. But there is also an scenario in which Trump doubles down and plays to “his audience” in areas where the president does hold immense power, including trade and military adventures. Therefore, there is, in my opinion, no escaping the fact that Trump poses a major threat to the world order, specifically to international trade and capital flows.

If this threat starts to unfold, market volatility will pick up as international capital will head for safer shores. The guiding principle for investments will then rest on three pillars: safe havens, but defined in a world where the US is the key source of concern, which probably means gold and bunds more than US treasuries; a greater share of capital will likely stay close to where it's created, which means that you’ll want to pick countries with current account surpluses, including the eurozone, and you want to stay away from Trump’s wars, i.e. primarily US, Chinese and Mexican assets.