'Be Worried, Be Very Worried is not a typical title for a Wall Street research report, so you have to take note when that's what UBS is saying about tomorrow's Greek election.

Now to understand the stakes of the Greek election, you basically have to understand one thing: There's been a big austerity/reform/bailout package agreed to, but full implementation is a long way off.

While the mainstream parties support ongoing implementation, there's growing support for more radical parties that don't support the current path. If they do well enough to prevent the mainstream parties from having a clear majority problem, the whole deal may be thrown into chaos.'

Read more: UBS On The Greek Elections: 'Be Worried, Be Very Worried'