Concentration risk is the risk that an investor takes on when they have a significant portion of their investment portfolio in a single security or asset class. The risk arises from the fact that if the single asset or security performs poorly, the entire portfolio will be impacted. This contrasts with diversification, where investors spread their investments across multiple asset types to minimize risk.
Concentration risk is particularly important in the context of portfolio diversification. Diversification is the practice of investing in a variety of different assets or asset classes to spread risk and minimize the impact of any single investment on the overall portfolio. By diversifying across multiple investments, an investor can reduce the impact of any one investment performing poorly.
However, if an investor is not careful, they may unknowingly introduce concentration risk into their portfolio by investing too heavily in one particular asset or sector. This can undermine the benefits of diversification and leave the investor exposed to greater risk.