It's been a reversal of fortunes for banks in 2012: financial stocks lead this year, up 26 percent, after performing the worst of all 10 S&P 500 sectors last year.

Consumer discretionary names are set to finish 2012 with strong gains as well, mainly due to the rally in home builders, home improvement stocks, and retailers. The iShares Dow Jones U.S. Home Construction ETF trades near four-year highs, up 74 percent this year, as housing has been the economic bright spot of 2012.

Hovnanian leads the builders, up 360 percent. Shares of PulteGroup, Ryland, KB Home, and Standard Pacific have all more than doubled.

Home Depot, a darling of 2011, remains on top, posting the second biggest annual gain on the Dow Jones Industrial Average, up 44 percent, behind Bank of America, which is up more than 100 percent. The do-it-yourself home improvement retailer benefited from both the housing recovery and super storm Sandy, which pummeled the East Coast at the end of October.

After falling 18 percent in 2011, financial stocks are on track for their largest gain in nine years, up nearly 26 percent.

A combination of clarity, fundamentals, and other catalysts created momentum for names such as Bank of America and Citigroup, according to Meredith Whitney, CEO of Meredith Whitney Advisory Group.

In fact, Bank of America holds the title for top gainer in the Dow Jones Industrial Average, up more than 100 percent in 2012, after being the biggest decliner last year.

Financials are also the best performing S&P 500 sector in 2012, outperforming the broader index for the first time since 2006.

The magnitude of the gains is significant, as the last time the sector outperformed the market by more than 10 percent was back in 2000.

Here is a look at the top performing stocks in the sector.

Since touching a nine-year low in September, shares of Research in Motion have been on a tear, up over 120 percent just ahead of the launch of its new BlackBerry.

Yet just as the stock continues to climb, so has interest in short positions, or investors piling on bets to sell.

At the end of last month, short interest reached a peak of 113.7 million shares, the highest level since January 2004. That would put short interest for the stock at about 22 percent.

Commodities are on track to halt four years of consecutive gains, despite large bets in related funds.

The S&P Goldman Sachs Commodity Index is down 0.03 percent this year, on track for its first annual loss since 2008, when it fell 43 percent.

At the same time, money invested in commodity funds is up 86 percent to $20.8 billion compared to 2011, according to data by EPFR Global.

Gold is the big winner in 2012, with nearly 84 percent of the funds invested in physical commodities ($16.7 billion) going towards the metal. Gold has gone up in price for 12 consecutive years, up about 500 percent in that period.

It has been somewhat of a mixed-bag for commodities in 2012. Soybean, soybean meal, wheat, corn, orange juice, and live cattle, for example, reached new multi-year highs at some point, while other names such as natural gas, cotton, sugar, and coffee fell to multi-year lows.

Here is a look at the best and worst performing commodities this year.

Sixty companies in the S&P 500announced share buyback programs worth at least $1 billion so far this year. Within the group, the biggest buying back came from Johnson & Johnson, repurchasing $12.9 billion worth of stock.

American International Group is also high on the list as the U.S. Treasury sold its remaining stake in the company last week, booking a total profit of about $23 billion.

Shares of the insurance company are up 53 percent in 2012, significantly outperforming the overall market, which is up 15 percent. In fact, of the 15 companies that have bought back stock at the fastest pace, only one is down for the year: International Game Technology.

December 16 marks the fourth year of the Federal Reserve's expansionary monetary policy. At nearly zero percent, U.S. interest rates have now remained at rock bottom levels for the longest duration in history.

By embarking on a historic expansion of monetary policy with low interest rates and massive bond buying, the Fed has kept a heavy foot on the pedal of the economy in its effort to jumpstart growth.

Although the economy has lumbered along and jobs remain scarce, investors have responded to the Fed's aggressive measures by sending stocks soaring. Since the inception of near ZIRP (zero interest-rate policy) in December 2008, the NASDAQ Composite is up 90 percent, followed by the S&P 500and the Dow Jones Industrials with gains of 56 percent and 48 percent, respectively.

Health care stocks reached a seven month high on Wednesday, helped by Aetna, which projected it will increase both revenue and profit next year ahead of major changes under U.S. health-care law.

The Morgan Stanley Healthcare Payors Index hit its highest level since April 25, up nearly 4 percent so far this month. In fact, out of the last 10 sessions, the index closed lower only once (Dec. 4, down 0.03 percent).

Within the index, shares of Coventry Health Care are trading at a new 52-week high. Back in August, Aetna announced plans to acquire CVH in a $5.7 billion cash-and-stock deal.

So far in December, Health Net, Aetna, Wellpoint, and WellCare Health Plans are leading the gains, up more than 6 percent. For the year, however, Amerigroup takes the top place, up 55 percent.

Facebook will be added to the tech-heavy Nasdaq 100 index prior to the open Wednesday, replacing Indian tech firm Infosys, which is transferring its listing to the NYSE on Wednesday.

As first reported by CNBC's Bertha Coombs, the addition of Facebook to the Nasdaq 100 will instantly give investors and traders of the popular PowerShares QQQ Trust ETF some exposure to the social media stock.

Shares of Apple are down nearly 24 percent from their record high of $700 back in September, and the stock is now trading in the feared "death cross."

That's when the 50-day moving average drops below the 200-day moving average and is considered a strong bearish sign. Apple reached that point on Friday. (Read more:Apple Passes 'Death Cross')

Apple's record after the "death cross" certainly isn't cause for optimism.

Since 2000, there have been six instances when Apple's passed through the "death cross." In five of those instances, the stock was down more than 5 percent one month after the crossing, with an average loss of 10 percent.

Apple shares rebounded on Monday after a weak open. Jefferies slashed its price target on the iPhone maker to $800 from $900.

The reversal of fortune has been jarring for a company which, just a few short months ago, had a high-flying stock that made it he world's most valuable company.

In 9 of the last 11 weeks, Apple closed in negative territory, losing over $150 billion in market cap value.

Volume continued to decline in the stock market during November, and some pros think it's because investors are worried about the "Fiscal Cliff."

As of Wednesday's close, volume on the New York Stock Exchange this month totaled 64 billion shares, the lowest this year (see chart below). That includes all trades executed on the exchange's various platforms.

There also have been big swings in the major indexes. The Dow's trading range this month was 819.26 points, while the S&P 500's was 90.92, the largest spread for both since June.

At the same time, the volatility index known as the VIX has not traded above 20 for four consecutive months, marking the longest streak since Feb. 2007, when it remained below that level for five straight months (Oct. 2006 to Feb. 2007).