There are different approaches to this

1) Some like to say invest $1000. When value of coins becomes $2000, they withdraw worth 1000 and then gamble with free money.

2) Some are investing only that money which they are ready to loose from day 1. They are also patient with the investment.

3) Some are investing for short term gains. I believe they are always in loss because their quality of life is affected due to tension and worries.