As you can see by this chart from 2007 on the distribution of US shares, the richest 1% of income earners in the population holds more than 38% of available shares, the next 9% of earners own a further 43% of the stock market's wealth, so combined, the top 10% of earners own 81% of the wealth. Leaving just 19% of what's left to be shared out to the remaining 90% of the population.
So when you wonder about who'll get hurt when the market crashes, don't worry...it won't be you, you don't hold jack!