Why is the Greek stock market getting hammered?
Three reasons: The banks, Greece's extreme left and the end of the bailout program.
Greek banks are likely to be forced to raise more capital in light of the AQR—the Asset Quality Review, which is underway in Europe and whose results are due on Oct. 26. Banks make up roughly 50 percent of the weighting of the Athens Stock Exchange, a much higher percentage than any other in Europe, so a decline in the banks leads to a disproportionate decline in the index.
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As for Greece's socialists, new polls—including one out on Tuesday—show they are leading other parties ahead of the country's next elections. If far-left leader Alexis Tsipras becomes prime minister, he promises a showdown with the European Union over "the program"—austerity—that Greeks have been living with since 2010, in exchange for a huge financial bailout.
Which brings us to reason three: the end of the bailout program.
The part of the Greek bailout program from the European Commission ends this year; the International Monetary Fund's portion of the program ends in a little more than a year. Greek Prime Minister Antonis Samaras wants to exit the program early, ahead of a key election in February, so he can campaign on giving Greece its sovereignty back. His argument is that Greece can borrow from the market rather than from the hated "troika"—the European Commission, IMF and European Central Bank. But borrowing from the market is much more expensive than borrowing from the troika, 7 percent versus 1 percent. Greek yields are rising, suggesting bond investors don't like the idea of Greece losing the troika yoke.