2018 has been, by pretty much every quantifiable measure, a nightmare for investors, but while most attention has been focused on the US and China, Europe has suffered worse.

The Euro Stoxx 50 index of Europe's biggest companies has fallen more than 15% so far in 2018.

European stocks have dropped three times more than the S&P 500, and are headed for their worst year since the financial crisis.

Economic woes in Germany, a budget crisis in Italy, Brexit, and France's social issues are all partly to blame for the market's horrible year in Europe.

External factors, like President Trump's trade war with China, and a continued tightening cycle from the US Federal Reserve are also hitting European stocks.

2018 has been, by pretty much every quantifiable measure, a nightmare for investors. The market has been permeated by bouts of crazy volatility and huge price swings, but has ultimately fallen sharply, with all three major US indexes set to end the year in negative territory.

A cocktail of factors, including the continued tightening of monetary policy around the globe, and worries about the economic impact of President Donald Trump's trade war with China, have pushed stocks lower after a near decade long run of gains.

Understandably, much of the focus has been on what's happening in the US, and to a certain extent China, but look beyond what's happening in the two biggest economies on the planet, and it is arguable that European markets are suffering even more.

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With less than a week of trading left in the year, the Euro Stoxx 50 — a benchmark of Europe's largest companies — has fallen more than 15% since the start of January, while the broader Stoxx 600 is down 13%. On Thursday, European stocks at large are trading at their lowest levels since 2016.

Market data analysed by Business Insider shows not only that the Euro Stoxx has dropped around twice more than the S&P 500 this year, but also that the index is set for its worst single year since 2008, during the heart of the financial crisis.

Four economies, four different sets of problems

A man holding a German flag attends a ceremony commemorating the 50th anniversary of the construction of the Berlin Wall at the Bernauer Strasse memorial on August 13, 2011 in Berlin, Germany. Sean Gallup/Getty Images

Problems abound in all four of the largest economies in the continent.

In Germany, which in recent decades has been Europe's economic powerhouse, growth is slowing and several of its most crucial industries are bearing the brunt.

Germany's Council of Economic Experts expects 1.6% growth for the country this year and only 1.5% in 2019, well below previous expectations and down from a bumper 2.2% in 2017. That's partly down to a torrid time for the country's automakers, long the backbone of Germany's manufacturing driven economy.

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BMW saw third-quarter operating profit plunge 27% amid greater competition in global markets. The Financial Times reported in November that new European Union greenhouse-gas emissions targets for automakers — the EU seeks to reduce emissions by 30% — are behind a 0.1% contraction in Germany's gross domestic product in the third quarter as car companies struggle to adapt.

In fact, Germany is looking so fragile that its benchmark share index, the DAX, has become a target for short sellers looking to profit from German industry's misery.

AQR Capital, a quant-driven hedge fund, is betting about €1.3 billion ($1.5 billion) on a decline in German stocks, joining other short sellers in swirling the index for returns after a brutal year for the country's equities, Business Insider reported last week.

Civil unrest hits markets

Protesters surrounded by tear gas during the December 8 protest in Paris. Getty Images

In France, while the protests of the so-called 'yellow vests' are largely a social issue, they are already being shown to cause damage both to the French economy, and in the markets.

The yellow vest protests are expected to halve the country's GDP growth by 0.2% from 0.4% in the fourth quarter, and retailers have lost an estimated €1 billion in revenue since the protests erupted in November. Last week shares in tourism-related companies saw their worst week in months, while investment bank RBC warned that the protests could impact French luxury stocks negatively.

Italy also has its problems. While the budget crisis that has gripped the country in recent months seems to finally have a solution, the country's government is volatile and highly eurosceptic, and it is not impossible that it will go back on the deal struck with the EU on Wednesday

Continued uncertainty over the budget has helped subdue the Italian stock market, with the benchmark FTSE MIB index dropping more than 10% since September.

Britain is also causing investors serious headaches, with Brexit becoming seemingly ever more uncertain.

"Trying to forecast market movements based on the outcome of unpredictable political events is a bit like trying to play darts while riding a unicycle," Laith Khalaf, senior analyst at Hargreaves Lansdown, said last week. "There is some measure of Brexit fatigue in place."

More broadly, business indicators are suggesting a significant slowdown across the eurozone, which will likely persist into next year.

"The German and French indicators are consistent with very slow growth while the Italian indices are clearly in recession territory," a note from Capital Economics said earlier this week.

Not only is Europe being buffeted by internal factors of its own making, but the external factors impacting markets around the world — tightening policy from the Fed, President Trump's trade war — are also helping to pull the European market lower.

Things could get even worse next year, after the Bank for International Settlements said this week that it expects further market turbulence to the downside in 2019.

"The market tensions we saw during this quarter were not an isolated event," Claudio Borio, one of the institution's most senior staff members said on Sunday.

If that prediction does come true, don't be surprised if Europe ends up bearing the brunt of the pain.