The most recent developments in the Greek national debt crisis led to the Danish C20 Cap - the top-tier stock market index for the Copenhagen Stock Exchange - opening with a 4.12 percent drop on Monday morning.
Investors panicked at the news of Greek PM Alexis Tsipras's unexpected decision on Saturday to call for a national referendum on the latest reform package that the International Monetary Fund (IMF) and other international lenders have demanded that Greece implement in return for more loans.
The Greek people will be going to the polls on Sunday to vote either yes or no to the package.
Greeks rushed to withdraw money from their bank accounts over the weekend, which prompted Tsipras to announce on Sunday night that banks in the country would close on Monday, a consequence of the decision on Saturday by the eurozone's finance ministers to halt Greece's financial bailout programme.
The banks are expected to remain closed for a week, while limits on withdrawals from cash machines have been set at 60 euros, according to media in Greece.
The C20 index bounced back a bit from its initial Monday morning plummet and after 10am was at a 2.24 percent drop, but analysts said that the initial opening shows that investors are rattled over the Greek default crisis.
“It's a very, very big drop,” Per Hansen, a stock analyst at Nordnet, told TV2 News.
“It is bordering on panic. It demonstrates that there is every reason to follow this [the Greek crisis, ed.] closely and it's a reminder that there is a huge risk of the Greeks leaving the eurozone,” Hansen added.
According to Ritzau, the C20 Cap index's biggest single-day drop was on June 6th, 2012, when it fell 3.19 percent due to concerns over the Greek general election.