The beginning of the third trimester of the year is traditionally down-time on Wall Street. This year, however, investors enter this slow period under the weight of several rather unique burdens: the threat of deeper and more direct US involvement in the Syrian civil war, the expected upcoming reductions to Federal Reserve stimulus spending, the ongoing effects of sequestration, and a potential upcoming fight in Washinton D.C. over the debt ceiling and budget.

With this in mind, now would be a good time to look back on the year, and take heart in the overwhelmingy bullish environment for equities that continually sent stocks to new heights throughout the better part of 2013.

The following are the Standard & Poor's 500 index's best performing stocks to date: 

#5: Boston Scientific (BSX)

Current Price: $10.58

2013 Gain YTD: 84.64 percent

Despite headwinds in the medical appliances industry, Boston Scientific has managed to post strong quarterly earnings so far this year. The company has made serious efforts to return to growth, plans to invest over $150 million in China over the next few years, and more importantly has a large number of promising treatments in development.

#4: GameStop Corp. (GME)

Current Price: $50.21

2013 Gain YTD: 106.94 Percent

The brick-and-mortar game retailer sells new and used video games and equipment for all systems, from desktop sets to computers. GameStop may seem like an unlikely candidate for this list, given the encroachment of mobile on the more traditional video game economy, as well as the rise of online retailers. With 6,500 stores in 15 countries around the world, however, the company is by no means a small one. The company may be taking advantage of a particularly good year for the business, however, as a number of highly anticipated games and gaming sets have been released, or are slated for release by the end of the year.

#3: Micron Technology (MU)

Current Price: $13.57

2013 Gain YTD: 114.04 Percent

Micron Technology is one of the only techs whose business is entirely devoted to the sale and manufacture of semiconductor memory, and its stock has been on an impressive climb so far this year. The company also doubled its size and reach with the $2.5 billion acquisition of Elpida Memory in July, a deal which keeps getting sweeter and sweeter as the Yen continues to struggle against the dollar.

#2: Netflix Inc. (NFLX)

Current Price: $283.91

2013 Gain YTD: 210.81 Percent

The popular streaming video service kicked off the new year with the success of its first foray into original programming, the show House of Cards. The immense success of the show, as well as the format in which it was released, with all episodes immediately available, were vindicated by the company’s first-quarter earnings report that showed a significant jump in subscribers. Since then, however, Netflix lost a great deal of very popular content after Viacom opted to move a vast amount of shows and programs over to the Amazon Prime streaming service. The stock has remained unfazed by the setback, however, and has continued to perform incredibly well.

#1: Best Buy Co. Inc. (BBY)

Current Price: $36

2013 Gain YTD: 210.95 

The brick-and-mortar retailer began the year with what looked to be an uncertain future. Stung by voracious competition from internet retailers such as Amazon.com (AMZN) , company founder Richard Schulze had been pushing hard to take the company private in order to turn matters around. Thankfully for Best Buy, however, Schulze’s efforts didn’t pan out, and the reins of the company were instead handed to new CEO Hubert Joly, who wasted no time in devising a price-matching scheme to compete with e-commerce and signing deals to lease valuable sales-floor space to major tech companies. Shares have been chugging along ever since, making Best Buy the S&P 500’s best performer of the year so far.

[Image Courtesy of Wikimedia Commons]