Coronavirus fears have pushed the US dollar to a three-year high

Investments considered safe in times of market turmoil have been rallying since the outbreak became Wall Street's number one worry in January. Cases continue to rise globally. The full financial and economic cost of the outbreak is incalculable.

But the United States, as well as dollar-denominated assets, are considered to be somewhat shielded from the outbreak's impact.

America's economy is less reliant on trade and exports than its peers, for example. That means the expected slowing of China's economic growth in the first quarter will hurt the United States less than it will other countries.

And the US economy has been going strong and is in its longest expansion in history.

The Atlanta Federal Reserve's GDPNow model forecasts US growth will accelerate to 2.6% in the first quarter. With a tight labor market and modestly rising wages, the American consumer, who is the backbone of the US economy, is in a good place.

Amid all this, the dollar has been rallying. No other currency stands a chance against the greenback's attractiveness, said Francesco Pesole, FX strategist at ING.

The ICE US dollar index finished the week at its highest level since April 2017, even though it traded in the red Friday.

That widely-used gauge measures the dollar against six other currencies, with the euro carrying the most weight in the index. Weakness in the shared European currency has helped the dollar, too. This week, the euro fell to its lowest level against the dollar in 34 months.

The dollar's strength comes at a bad time for America's multinational corporations. It can weigh on their foreign earnings, which are converted back into the US tender for their earnings reports.

Paired with the cost of the virus outbreak, this could be a double blow for companies.

Apple was the most high profile company to announce it won't meet its first quarter revenue guidance due to the outbreak's impact. Other companies are expected to make similar announcements before the next earnings season kicks off.

--Julia Horowitz contributed to this report.