$10M and hedge fund
According to U.S. Trust Insights on Wealth and Worth -- Survey of High Net Worth and Ultra High Net Worth Americans 2012 Highlights,
"as of the end of 2011, there are nearly 2 million households in the U.S. with more than $3 million in investable assets, including 1,074,000 households with $3M – $4.9M, 654,000 households with $5M – $9.9M and 196,000 households with greater than $10M [Phoenix Global Wealth Monitor]."
Assuming a $10M HNWI (High-Net-Worth-Individual) can have $5M investable assets, it could be estimated that there are in total 654K+196K = 850K households that have $10M net worth. Given the fact that the USA consists of 118M households, the $10M household percentage is merely 0.85M/118M = 0.72%.
$10M is virtually impossible for regular small business owners to accumulate in their whole life span. The number is also extremely hard for CEOs and CFOs of medium-sized companies to make in their entire life. Top executives of big companies can reach such an amount, but it's not from W2 income, instead, it's from company stock grants, stock options and investing savings in the stock market. For people whose total assets are less than $10M, the only way to achieve $10M is through investing in the stock market.
In short, unless somebody has sizable private shares of a company which goes IPO or just simply inherits good fortune from parents, in order to achieve $10M, the only way is investing in the stock market.
VHNWIs (Very-High-Net-Worth-Individual) who have $10M, multiple-$10Ms and beyond, must invest most of their assets in the stock market for keeping value, growth or both.
It's a game of riches that average people don't even have basic concept or common sense at all!
Hedge fund business doesn't need to build a factory, nor does it need to manufacture a product, and running the business even doesn't need an office!
It's been relentlessly emphasized that such business relationship must be long term because the final return has to rely on compound interest on the basis of consistent profitability and hence short term makes no sense. Obviously, developing long term relationship is absolutely based on mutual trust - the foundation of any relationship, particularly understandably in such money-dealing-only linkage!
These are reasons on why hedge fund industry is a very strictly regulated business. Most importantly, it's ultimately demanding on fairness and trust for both service provider and clients. People who have the big picture vision in mind would never put their trustability at stake!