5 Stocks to Buy in the September Sell-Off

History has shown that a market sell-off is a great time to add quality companies to your portfolio. Although no one can predict when that will happen, a 10% drop occurs about once every two years. That's why I'm highlighting five high-quality companies to buy if the most recent swoon persists.

I can't tell you where Adobe (NASDAQ: ADBE), Markel (NYSE: MKL), Take Two Interactive Software (NASDAQ: TTWO), Vertex Pharmaceuticals (NASDAQ: VRTX), and Boston Beer (NYSE: SAM) will trade next week or next month. But I'm confident they will significantly outperform the market over the next three-plus years. Here's why.