Not perpetually, but there are helpful strategies.
For the past 6 years the SMI portfolio averaged 11.9%. This includes 2000 and 2001.
SMI is an inexpensive (~$100/year) monthly newsletter. It uses a simple, safe, and sound approach to recommend mutual funds to buy and sell on a monthly basis to maintain a portfolio of 20 or so funds. In a nutshell, SMI picks funds that have recently done well relative to their peers and then sells them when they fall relative to their peers. SMI realizes that one of their chief contributions is telling you when to sell. SMI openly publishes the reasons and data used in their recommendations, which anyone can understand. You will probably spend 20-30 minutes per month managing your portfolio. The newsletter and/or website also contains articles on mortgages, debt, college financing, and other financial matters.
The SMI performance history for the past six years can be found at the url below.
Consider investing broad index funds which are quite safe, and would have return in 10% range over period of 5-10 years. Consider funds like VTI, VXF, SPY and there are many others, you can research on finance.yahoo.com.