The big macro can cause big moves in the market. What does today's headline macro news mean for your portfolio?

What's happening: Standard & Poor's cut Spain's sovereign credit rating for the third time in as many years. The action brings Spain's rating down to AA-, and S&P continues to list the country's outlook as "negative."

In plain English, please: When it comes to Europe's fiscal crisis, we hear a heck of a lot about Greece. And that makes perfect sense, since that country is in the direst financial position. However, it's important to remember that it takes more than a "G" to make up PIIGS (which stands for Portugal, Ireland, Italy, Greece, and Spain). S&P's downgrade is a reminder that other, much larger, economies in the EU aren't in terribly good shape, either, and that a solution for Greece's woes means more than just respite for that country.

In theory, a credit downgrade means that Spain could face higher borrowing costs to reflect the country's dicier outlook. I say "in theory," though, because that will happen only if bond investors haven't already been factoring in the concerns that led to S&P's adjustment.

Stocks to watch: What's bad for Spain broadly is bad for the country's businesses. Major Spanish banks like Banco Santander (NYSE: STD) stand to feel some heat from the downgrade, as do Spanish companies such as Telefonica (NYSE: TEF) that have heavy debt loads. Looking at the picture more broadly, we can see that threats to Spain's health threaten the entire EU region and could affect larger European banks such as HSBC (NYSE: HBC) and Deutsche Bank (NYSE: DB), as well as large multinational companies that do business in the region.

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