1.   That shook the financial markets even further and sent the ruble out of control.

2.   Nervousness over the talks with the IMF and hawkish anti-Western statements by Russian politicians about the NATO airstrikes have sent the ruble tumbling this week.

3.   Recent increases in the money supply have contributed to rising inflation and sent the ruble into a steady nosedive.

4.   Those concerns have sent the ruble lower, and there are signs things could worsen.