Just how much will it cost to fix Europe?

That is the question on investors' minds all across the globe. The markets fell today on fears that the proposed bailout of Spain's banks won't do enough in the long run to keep the Eurozone from crumbling apart.

Why? Partly because Spain is now the fourth European country to ask for a bailout – Greece, Italy, and Portugal have as well. Partly because no one knows how much it will actually cost to fix the European economy – some estimates run as high as several trillion dollars, dwarfing their bailout fund.

But also because the overall economic picture is just too uncertain and unpredictable right now. And to top it all off – the American taxpayer could end up on the hook for all this.

Stocks fell today on the heels of the announcement that Spain will be getting a $125 billion bailout in an effort to prop up Europe's economy.

Erin Burnett talks to Wolf Blitzer about why early optimism among investors was soon replaced by doubt and anxiety and whether or not this bailout will do anything in the long run. Tune it at 7PM/ET for Erin's full deconstruct.

CNN's Erin Burnettexplains how the European debt crisis can take a bite out of your financial future. Knight Capital Managing Director, Peter Kenny and Sr. Editor-at-Large, Fortune Magazine, Shawn Tully are OutFront.