Stocks typically post gains during Thanksgiving week, but all bets are off when it comes to this market.

"Heading into the holiday shortened Thanksgiving week, there is a lot of talk about the bullish seasonality," said Jonathan Krinsky, chief market technician at MKM Partners, in a note. " Of course this year has been anything but ordinary. By now it is quite obvious to most participants how narrow breadth has been... Despite seasonal tailwinds, we remain hard pressed to get too optimistic on the index level."

The market's main benchmark, the S&P 500, has risen six times over the past decade during Thanksgiving week, with an average 1.9% increase.

But even if stocks end this week on a positive note, there are plenty of reasons why the traditional year-end Santa Claus rally might not show up this year.

Global fears made for rocky trading on Tuesday with stocks beginning the day in the red before turning positive on a surge in crude prices. The S&P 500 was up 0.3%, the Dow Jones Industrial Average added 0.35%, and the Nasdaq rose 0.13%.

The energy sector moved higher as crude oil rallied on a possible stop in oil trade between Turkey and Russia. West Texas Intermediate rose 3.1% to $43.05 a barrel. The Energy Select Sector SPDR ETF (XLE - Get Report) added 2.4%. Crude had closed lower on Monday after Venezuelan oil minister predicted oil prices in the mid-$20s. 

"The petroleum markets are staging a short-covering rally, sparked at least in part by Turkey's downing of a Russian warplane near its border with Syria," Timothy Evans, Citi energy futures specialist, wrote in a note. "The market reaction so far suggests a chilling of relations and a drop in trade between the two countries rather than the start of a major war."

The Turkish military overnight shot down a Russian fighter jet on the Syrian side of the Turkey-Syria border. Officials said the aircraft intentionally violated Turkish airspace. The incident marks another flare-up in already-tense relations in the region. Russian President Vladimir Putin said the attack was a "stab in the back by the accomplices of terrorists," accusing Turkey of abetting the Islamic State by selling its oil.

Weaker data on Tuesday kept the possibility of a December rate hike from the Federal Reserve in question. Consumer confidence fell to its lowest level in 14 months in November, the Conference Board said Tuesday. Sentiment was hit by increasing pessimism over the labor market with a rising number of people saying that jobs were harder to find.

"In keeping with this theme of looking bigger picture ... it's important to not focus on one single piece of economic data that's released today or tomorrow and extrapolating them to a conclusion about what the Fed might do on December 16," said Christopher Vecchio, Currency Analyst at DailyFX. "While it will be easy to overreact to one good or one bad print ... the only thing that matters is the aggregate impact of the data on rate expectations beyond [the next meeting." 

Third-quarter GDP in the U.S. was revised up to 2.1% growth, as economists expected, from a previous reading of 1.5%, according to the U.S. Commerce Department. The upward revision was driven by less inventory accumulation than previously expected.

Bill Ackman's Pershing Square raised its stake in Valeant Pharmaceuticals (VRX) as shares continue to face pressure from accusations of sales fraud. The activist investment firm raised its stake to 9.9% from 5.7%. Valeant shares have nearly halved in value since mid-October.

Activist investor Carl Icahn has disclosed a new 7.1% stake in Xerox (XRX - Get Report) to become the company's second-largest shareholder. Icahn called the company's shares "undervalued" and said he was looking to gain a position on the board.

Microsemi (MSCC) agreed to acquire PMC-Sierra (PMCS) for $2.5 billion after Skyworks Solutions (SWKS - Get Report) bowed out of negotiations for the semiconductor company. PMC-Sierra allegedly backed out of any merger after Skyworks did not modify its offer. Skyworks said it is is owed $88.5 million in termination fees from the nullified merger agreement. PMC-Sierra shares were down 1.6% on Tuesday.