Total global meltdown: Is oil to blame?

If Europe is any indication - it could be a messy Tuesday on Wall Street today. London's FTSE (^FTSE) was down more than a percent this morning, driven lower by a decline in Tesco - the UK's biggest super market.

It's not just the UK either - Greece is at risk for (yet another) round of instability after announcing voting for a new president will begin next week. It's a largely ceremonial post, but given the fragile state of government in Greece, it could actually topple the government and lead to another round of elections in Europe's most indebted country.

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That may be all Greek to you - but today not shaping up to be a pretty one stateside either. Monday was the S&P 500's (^GSPC) worst day since October 22nd with the index spelunking .7% lower. For want of anything else to discuss traders are citing concerns that the Fed may eliminate the words "considerable period" in regards to how long interest rates will remain at zero.

I don't personally know anyone who genuinely invests real money off Fed parsing. Dismiss that as a real catalyst.

The biggest risk facing stocks isn't Fed verbiage but dislocation. A dislocation is what traders call it when asset classes start trading in extreme, unexpected ways. You don't get more extreme than what crude is doing. WTI crude was down another 4.2% yesterday. The Dow leaders to the downside were Exxon (XOM) and McDonald's (MCD).

Related: Why oil's free fall shouldn't keep you from Exxon, Chevron

Exxon Mobil's decline makes sense given the drop in crude. The disconnect part is that McDonalds posted negative 4.1% comps in the U.S. Say what you want about McDonald's company-specific failings, they still make nature's perfect food in the form of the McDonald's French Fry.

Based on government data regarding what consumers spend on gas the average American is saving about $170 a month on fuel compared to what they spent last year. That's like finding an extra $40 in the laundry every week. You don't start buying diamonds but you would, at least in theory, be more apt to buy some fries.

Related: McDonald's awful November results set stock up for worst day of 2014

Retail sales have been decent, but at least so far, it's hard to say the net impact of falling prices has been an economic pick-up. In theory US consumers are saving hundreds of millions a day on gas but no one can seem to find where the money is going. Until they do, or more importantly until crude stops free-falling look for stocks to remain a vulnerable to gossip and gaps lower in price.

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