The day of reckoning for the Wall Street is here. Donald Trump is officially leader of the free world and the level of consternation in the market is palpable.

Check out: The Dow’s biggest surge came under this president

That is not to say that equities won’t continue to carve out fresh records, spurred by animal spirits; or that Trump’s promise to “make America great again” won’t come to fruition, leading to halcyon days for investors from the lowest sociopolitical rung to the deepest-pocketed 1%. The stock market Monday, in the start to the first full week of Trump’s presidency, ended trading modestly lower.

“America will start winning again, winning like never before,” he said as a part of his inaugural speech on Friday, emphasizing that he will promote policies that put “America first.”

Mostly, the hand-wringing has centered on the “unpresidented,” unscripted, Twitter-happy nature of it all. The boundless uncertainty of how a Trump presidency will influence stocks, bond markets, commodities, the flow of trade, and economies across the globe has investors tied up in knots.

Here’s how Mark Grant, chief strategist of Hilltop Securities, put it in a Thursday note:

“In my almost 43 years on Wall Street, I am not sure that I have ever seen so much consternation than at present. It is not just differences of opinion but it is a quite real fear of the unknown, I suppose. People just don't know what they are getting into or where the country is heading. No surprise, I think, as tomorrow the Present will have a material break with the Past and the Future is a calculated guess.”

Also read: Investors buy up volatility ETFs going into the Trump era

U.S. markets jubilantly vaulted higher in the wake of Trump’s surprise victory over Democratic rival Hillary Clinton, leaving many investors, including some of the smartest, like billionaire George Soros at least temporarily flat-footed.

The Dow Jones Industrial Average DJIA, -0.90% has returned about 8% since his election victory Nov. 8, the S&P 500 index SPX, -1.20% boasts a return of 6.6% and the Nasdaq Composite Index COMP, -1.33% has seen a return of more than 7% during that period, according to FactSet data (see chart below):

Many pundits predicted pain and anguish would follow if Trump emerged from the presidential election victorious. Meanwhile, the yield on the 10-year Treasury note TMUBMUSD10Y, 0.690% has climbed to 2.475% from 1.865% on Nov. 8, on expectations of a pick up in inflation and real rates.

The basis of the moves has been the hope that Trump will deliver on campaign promises that include a ramp up of infrastructure spending and a repeal of rules that critics say have hemmed in the nation’s largest financial institutions. A reduction in taxes also has been proposed.

Read: What President-elect Trump means for the stock, bond, other markets

With the presidential inauguration looming, however, stocks have receded somewhat, leaving the Dow down 0.2% lower for the month, as of Thursday’s close. The S&P 500 and Nasdaq are showing signs of life, with gains of 1.1%, and 2.9%, respectively, which suggests that the so-called Trump rally hasn’t entirely unraveled, even if it has taken a bit of breather. However, a loss of momentum has forced investors to contemplate the future after a relatively torrid run higher.

“At present markets do not seem to be anticipating problems either in terms of delays by Congress, or in boosting growth significantly. Such optimism is likely to be questioned: prepare for a reappraisal of the Trump trade,” said Keith Wade, Chief Economist at Schroders.

See:How the ‘Trump rally’ stacks up to other postelection stock market gains

Goldman Sachs Group GS, +0.25% CEO Lloyd Blankfein, whose bank’s shares have enjoyed the biggest portion of the Trump bump and is seeing a goodly number of its alum head to the real estate mogul’s administration, including Treasury secretary nominee Steven Mnuchin, isn’t sure what happens after Trump officially takes office.

“I’m dying to look back at this and like the outcome,” Blankfein said on Wednesday during an interview on CNBC at the World Economics Forum in Davos, Switzerland.

In one chart:How stocks perform in a new president’s first 100 days

David Lafferty, chief market strategist at Natixis Global Asset Management, told MarketWatch that Wall Street had initially been too eagerly focused on the benefits of a Trump presidency and not sufficiently paying attention to the potential negatives, including his protectionist posture.

Lafferty says, however, that “in recent weeks, the market has come to take a more measured view of Trump’s proposals. Creating legislation is never as easy as it seems, even with both houses of congress under Republican control.”

The Natixis strategist is still hopeful: “If Trump can tone down the antitrade rhetoric, his platform of spending, lower tax rates, and deregulation should bolster growth. But the market got ahead of itself in the initial weeks postelection and now appears to be suggesting a more realistic view,” he told MarketWatch.

Many on Wall Street are doing the calculus and determining that there are many known unknowns to grapple with, borrowing a term from former Secretary of Defense Donald Rumsfeld.

Here’s how research firm Acritas Research has depicted the risks and benefits of a Trump presidency (see infographic below):

Source: Acritas Research

Acritas estimates that nearly three-quarters of legal officers inside U.S. organizations are bracing for significant changes in how companies run and operate their businesses under Trump.

Trump also comes to power as parts of the European economy are still stumbling along and amid concerns about the U.S.’s tense relationship with China and Russia—not to mention the unrelenting fears around terrorism and climate change.

Check out:Trump’s ‘bromance’ with Putin poses a major risk for U.S. corporations

Prominent investor Peter Schiff, CEO of Euro Pacific Capital, said this of the coming Trump administration in a recent research note:

There is much we don’t know about how the Trump presidency will play out. Will the Wall get built? Who will pay for it? Will it have at least some fencing? Will repeal and replace happen at exactly the same time? Will Trump throw a ceremonial switch? Will there be a Trump National Golf Course in Sochi? It’s anyone’s guess. But of one thing we can be fairly certain. President Trump is very likely to preside over the largest expansion of Federal budget deficits in our history.

Soros doubled down on his belief that Trump is bad news in a TV interview with Bloomberg on Thursday, and not just for the U.S. stock market.

Still, there is a prevailing view that the U.S. economy is on a firmer footing. Federal Reserve Chairwoman Janet Yellen said as much during a speech on Wednesday.

Ralph Bassett, head of North American equities at Aberdeen Asset Management, said he’s looking for corporate-earnings growth, which could help push the market higher. “We believe the economy is on sound footing and expect earnings growth for to remain positive in 2017 and indeed we believe earnings growth rates should be the most significant aspect to share price performance over the next few years,” he told MarketWatch.

In the 72 days since Trump won the election, he has jawboned the dollar DXY, -0.07% lower, and continued his threats to build a wall along the U.S.-Mexico border, blasted the press, accusing them of reporting fake news after uncorroborated allegations that members of Trump’s team held clandestine meetings with Russian officials surfaced.

He also has taken credit for multinational corporations, including General Motors GM, -1.10% , Wal-Mart Stores Inc. WMT, -0.85% , United Technologies Corp. US:UTX unit Carrier Corp., keeping jobs in the U.S., and for some fostered a sense of economic optimism.

Read:Why NBC News isn’t ‘fake’ for questioning Trump job-creation claims

Time will tell Trump’s long-term effect, and for the market the waiting will be the hard part.