Diversify to Avoid Being Burned by Underhanded Executives Looking to the Past to Determine Which Stocks to Choose

Limit Exposure to Unexpected Things

Having a broadly diversified portfolio is just a more prudent way to invest in small companies. The myriad of unexpected things that can happen, which might be short-term glitches for a bigger company, can take a small company down. We don’t want to be overexposed to that.
Source: http://www.valueinvestorinsight.com/