The calendar year has officially closed out, and with the benefit of perfect hindsight, here is an overview of five asset classes and the specific investments in each class that have netted investors some of the biggest gains of the year. (For related reading, also check out The Biggest SEC Investigations Of 2010.)
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Wabash National (NYSE:WNC) - YTD Return: 528%
Truck trailer manufacturer Wabash National started the year at under $2 a share and steadily made its way into double-digit territory by the end of a December for one of the more impressive gains for a stock listed on the Big Board. The firm will likely remain stuck in the red in terms of profitability for the year, but its sales have recovered from the depths of 2009, as has sentiment that this cyclical firm will see brighter days ahead.

China Shen Zhou Mining (NYSE:SHZ) - YTD Return: 1,200%
Chinese-based mining exploration form China Shen Zhou started the year at under a buck per share and took its time heading into the stratosphere. A rally from October on brought the stock to more than $9 as year-end approaches. Sales and profits remain scant, but that hasn't stopped speculators from their zealous optimism.

Dynamic Gold & Precious Metals I - YTD Return: 70.94%
According to a Morningstar screen, the best fund for the year was a fund that invests primarily in publicly traded gold mining firms. This is not surprising, given the run gold bullion has had during the year, nor is the fact that it handily beat other funds in its category and other funds in competing asset classes.

Encompass - YTD Return: 59.68%
This fund had a stellar year holding a diversified mix of energy and commodity companies across the globe. Demand for the natural resources benefited from an improved economic outlook and made this the second best performing fund, according to Morningstar.

ProFunds Internet UltraSector Inv - YTD Return: 56.25%
The third-best fund in Morningstar's screen process consisted of a fund that counted Google, Amazon and eBay as its top holdings. Given the impressive performance of these and other Internet firms, it's not difficult to see that the fund's performance was among the best to be found for all of 2010.

ProShares Ultra Silver (NYSE:AGQ) - YTD Return: 171.24%
Along with gold, silver had a strong year and pushed this ETF to the top of the list, also according to Morningstar. Commodities and precious metals did extremely well overall, but those that piled into gold or silver did the best for 2010.

Barclay's iPath ETN (NYSE:BAL) - YTD Return: 97.06%
Cotton prices skyrocketed as the year was winding down, so any bullish bets on the key input to apparel and related clothing would have netted you big money during 2010. A classic supply and demand imbalance was cited as the main reason, with increased consumer spending after the recession putting pressure on lower supply from flooding in key production areas in Pakistan and bad weather in vital parts of China and India.

Direxion Daily Small Cap Bull 3X Shares (NYSE:TNA) - YTD Return: 73.49%
Using leverage in an upmarket to increase long exposure is a solid, albeit risky way to strike it rich. This fund seeks to return 300% of the daily price performance of the Russell 2000 Index. Small and mid-caps were among the two best performing stock categories for the year, so investors that bet big in either space ended up with big gains, and those that employed even more bullish bets in the spaces saw huge upside.

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JinkoSolar Holding (NYSE:JKS) - YTD Return: 82%
As with stocks in general, those with a China influence were among the best performers for 2010. JinkoSolar sells solar products in the country and was met with great investor enthusiasm for its shares when it went public in May.

Fabrinet (NYSE:FN) - YTD Return: 94%
Fabrinet is based in the Cayman Islands and sells electronic equipment such as optical components and related telecom gear. Investors see strong growth potential in the stock as new markets in industrial lasers and other rapidly growing markets hold great promise going forward.

Camelot Information Systems (NYSE:CIS) - YTD Return: 123%
Another Chinese firm, the company combines information technology (IT) with financial services and sells IT applications to major corporate financial service firms in China. A burgeoning class of new investors will certainly feed demand for Camelot's services over the long haul, and so far has made big money for investors since going public in July.

Alternative Assets
Alternative assets include those other than stocks, bonds, mutual funds and ETFs. Hard assets, such as the gold and silver investments related above do qualify and were two of the best performers during 2010. Cotton and other commodities also qualify and were also cited as subsets of the above traditional asset classes. (For more on the year that just passed, see Memorable Money Quotes Of 2010.)

For the latest financial news, see Water Cooler Finance: Goodbye 2010 (And Good Riddance?)