You can't lose what you don't have.
The reverse is true for people with Millions in a stock virtual portfolio. Phil points out that the reson you don't run a large hedge fund trying to make 100% gains is that the people who invest in those funds are more interested in what we call "preservation of capital" rather than generating wealth. Generally, the people who have $1M of investable cash to play the markets have already achieved a great deal of success, often by taking their own risks along the way. For most of us, $1M is hard to come by and, while we want to put that money to work - we certainly don't want it wondering off and joining the circus.
As a high net-worth investor, you need to decide how to diversify your assets to suit your long-term goals. We're not going to get into that here - let's just say that if you want to gamble and go for some of our "more exciting" plays, perhaps allocate a portion of the virtual portfolio to those. Whether that's 5% or 10% or 30% is up to you but it is good to fence off your risk to a sensible, manageable amount that you really can afford to lose while keeping the bulk of your market allocation well diversified and well-hedged.
I have my own 5% Rule. Phil's famous 5% Rule deals with the predictable movement of stocks in their trading ranges but my 5% Rule, which Phil also agrees with is simply "Do not put more than 5% of your virtual portfolio in the stock of any one company!” This is so much easier said than done for many reasons!!
[1] Transition to Large Numbers
Moving from a 5 or 6 figure account to a 7 figure account has a profound impact on many traders. In
