Let’s be direct: You don’t know much about the coronavirus, and neither do I. And perhaps most of all, neither does Donald Trump — but it doesn’t stop him from talking about what it will (or won’t) do to your money or to his re-election prospects.

A day after Trump unleashed a team of advisors to talk up the market and claim that coronavirus is all but under control, the Dow Jones Industrial Average lost another 690 points by mid-afternoon Tuesday. The market’s now off about 8 per cent since February 12th.

“The Coronavirus is very much under control in the USA,” Trump tweeted Monday. “Stock Market starting to look very good to me!”

Shocking, I know, but the President was making things up.

Nevertheless, understanding what Trump is up to isn’t hard. Here are some things we know for sure.

First, Trump badly wants the stock market to make his case for re-election. He talks about it all the time — all the more because his market has been fairly average. With the slump over the past week, it’s flirting with mediocre. Let’s look at the numbers.

With the decline this week, the Standard & Poor’s 500 index is up 39 per cent since Trump was sworn in, in January 2017. At the same point in his first term, President Barack Obama was sitting on a 65 per cent gain — 97 per cent if you measure it from March 2009, when the S&P devilishly bottomed out at 666.79 — an omen of money-making to come.

Better, Obama called the shot — just as Trump is trying to now. On March 4th, days before the bottom, Obama said this: "What you're now seeing is profit and earning ratios are starting to get to the point where buying stocks is a potentially good deal if you've got a long-term perspective on it.”

Unlike Obama then, Trump now is being overtaken by fresh information in real time. Today, the US Centers for Disease Control warned that the Covid-19 virus will likely spread in the US and urged local governments to begin emergency planning — and Trump appeared to confuse the status of a coronavirus vaccine with a vaccine for Ebola, an outbreak that occurred more than five years ago, at a news conference in India. Little wonder that a rally in stock futures before the opening turned into a selloff by 10.20am, 50 minutes after stock markets opened.

This is very different to Trump’s two years of back-and-forth with the markets over trade policy. Markets follow what he says about trade — costing you money when he waxes protectionist in public, then letting you make it back when he announces even limited deals with trading partners — because Trump himself controls when tariffs are imposed and how much they cost. His words have consequences then.

But obviously, Trump has no control over coronavirus worth discussing. He only kind of knows it’s different than Ebola, which happened years ago, in a different part of the world, with fewer US cases than we’ve already seen with Covid-19.

Last week, he was arguing that the new coronavirus was no problem because it will peter out by spring, when flu season ends. This week, he’s panicking.

Even if Trump’s partly right about spring, though, coronavirus will likely do significant election-year damage by then. Just when manufacturing was climbing out of a recent downturn caused by trade policy, coronavirus threatens global supply chains that depend on Asian factories. Goldman Sachs cut its estimate of first-quarter gross domestic product growth to a 1.2 per cent annual rate on Monday — implying a 40 per cent slowdown from fourth-quarter 2019’s growth.

If that’s true, that puts Trump in almost the same position Democrats were in early 2016 — defending a short slump (the economy averaged 1.1 per cent for three quarters beginning in late 2015) caused by a contagion coming out of China. Back then, it was fears of China’s debt load; now, it’s fears of the Middle Continent’s viral load.

Coronavirus: Streets around world left empty Show all 10 1 /10 Coronavirus: Streets around world left empty Coronavirus: Streets around world left empty A man wearing a face mask crosses a road in Wuhan, the epicentre of the novel coronavirus outbreak. Reuters Coronavirus: Streets around world left empty A view of the empty entrance to the UniversitÃ Cattolica (Catholic University) in Milan, northern Italy, on 24 February, 2020. EPA Coronavirus: Streets around world left empty Empty streets in Daegu, South Korea, on 23 February, 2020. EPA Coronavirus: Streets around world left empty Empty streets in Daegu, South Korea, on 23 February 2020. EPA Coronavirus: Streets around world left empty A lone sanitation worker sits near the closed Hankou Railway Station in Wuhan, Hubei province, China, on February 24, 2020. Reuters Coronavirus: Streets around world left empty A view of a deserted street in Codogno, northern Italy, on February 23, 2020. EPA Coronavirus: Streets around world left empty Italian police officers set a road block in Codogno, Northern Italy, on Monday, Feb. 24, 2020. AP Coronavirus: Streets around world left empty A supermarket closed in Codogno, one the northern Italian towns placed under lockdown, on February 23, 2020. EPA Coronavirus: Streets around world left empty A lone cyclist wearing sanitary masks pedals in the center of Codogno, Northern Italy. LaPresse via AP Coronavirus: Streets around world left empty An empty road at the entrance of the small Italian town of Codogno on February 23, 2020. AFP via Getty

That’s not where he wants to be.

So if we know why Trump is talking his book, in Wall Street parlance, what should we do about it?

As voters, that’s up to each American individually — with Russian input on Trump’s behalf, of course.

As investors, it means to wait. The worst of this is not known yet. Possibly, it was last week. More likely, the crisis will play out over a few months, slowing the economy and the market through a good bit of early 2020. Already, the brisk gains that led off the year have evaporated — as of today, the S&P is down for 2020.