Small-cap stocks are riskier than their blue-chip peers, but they can also deliver incredible gains. The trick is finding solid businesses that the rest of the market is overlooking, putting your emotions aside to ride out volatility, and remembering to focus on the long-term trajectory of the company. It's not easy, but it isn't impossible to find multibagger stocks flying under the radar, either.As 2017 nears its end, investors sifting through a historically expensive stock market may want to consider a few small-cap stocks to buy.