Small and mid-cap stocks don’t get as much attention from bankers, third-party analysts, and the media, which often leaves them less efficiently priced than their larger peers. Generally speaking, hedge funds take advantage of this by dedicating their research teams to work on the little guys, and consequently, they generate a significant portion of their alpha from the small-cap world. At Insider Monkey, we’ve empirically tested this phenomenon, and according to our own analysis, investing in the hedge fund industry's top small-cap picks has generated an alpha of about 120 basis points per month. We started publishing a quarterly newsletter at the end of August and shared the stock picks of this strategy. Since then, until the end of December, this strategy returned a whopping 14.3% versus 2.1% for the S&P 500 index (learn more about our small-cap strategy). Let’s take a look at the top small-cap stock picks of one hedge fund in particular: George Soros’s Soros Fund Management. The stocks presented here have market capitalizations between $1 billion and $5 billion, which is consistent with the criterion used in our strategy (see all of George Soros’s favorite stock picks). According to its last 13F filing with the SEC, the No. 1 small-cap stock in Soros’s fund was Adecoagro SA (NYSE:AGRO).  With a little under 26 million shares, Soros owns approximately 21.3% of Adecoagro’s outstanding shares. Since its U.S. IPO roughly two years ago, the agricultural holding company has lost 25.5% of its value, but shares have been in the green since the start of 2013. Now, the crux of Adecoagro’s bullish thesis lies in its exposure to one of the best asset classes out there for the long, long run: arable land. The company owns around 40 different farming properties throughout Argentina, Brazil and Uruguay. Though most investors are aware that farmland prices have been skyrocketing in the United States, Brazil, for example, has also seen the average value of its arable land increase by nearly fourfold over the past decade (via Informa Economics FNP). Uruguayan and Argentinian farmlands have experienced a similar boom. Another benefit of Adecoagro’s portfolio—which is most heavily concentrated in Argentina—is its crop diversity, which reduces its exposure to one commodity in particular, like corn or wheat. At a mere 14.9 times forward earnings, shares of Adecoagro are cheap at the moment, and the sell-side expects the company to finish 2013 with earnings of 63 cents a share—nearly twice its 2012 forecast. Who's the best of the rest?