Entrepreneurship is the engine of personal wealth creation the world over. In a study of 111 entrepreneurs all 50 years old or younger, with a net worth (including their businesses) of $50 million or more, 87.4% said that the success of their companies is the way they became personally wealthy. Moreover, they are currently intensely focused on growing their companies which will add to their personal wealth.

Only 10.8% said investing outside their business, is the way they became personally wealthy. While their businesses provided the monies for outside investments, these investments in everything from real estate to cryptocurrencies have done quite well in making the entrepreneurs ultra-wealthy. The remaining 1.8% cited other approaches to amassing meaningful personal wealth.

As entrepreneurs become affluent because their businesses are doing well, they can amass wealth outside their companies. All 111 successful entrepreneurs had—on average—investment portfolios of $9.1 million. The monies in their investment portfolios ranged from $1.4 million to $31.7 million.

Every successful entrepreneur reported that although they are very interested and attentive to the performances of their investment portfolios, they are more concerned with mitigating taxes. This was even the case for the entrepreneurs who reported that investing outside their business, is the way they became personally wealthy.

“While investing is very important to the ultra-wealthy, no one can guarantee a portfolio's performance over time,” says P.J. DiNuzzo, Founder and Lead Consultant of DiNuzzo Middle-Market Family Office and author of the Wall Street Journal bestselling book, The DiNuzzo Middle-Market Family Office™ Breakthrough: Creating Strategic Tax, Risk Cash-Flow and Lifestyle Options for Successful Privately-Held Business Owners and Affluent Families, “On the other hand, we know from experience the tax savings we can deliver to successful entrepreneurs and affluent families because of what we have achieved for clients through our in-house tax department. When working with successful, closely held business owners, we’re often able to find significant ways to mitigate their tax bills and they consistently agree that this is more important to them than their investment results.”

When it comes to the taxes generated by their investment portfolios, only 8.1% of them say they are taking steps lower these taxes. “One way the ultra-wealthy are lowering the taxes on their investments portfolios is by wrapping the investments in life insurance,” says Frank Seneco, President of the advanced life insurance planning boutique, Seneco Global Advisors. “These policies are known as private placement life insurance. When the private placement life insurance policies are structured in a certain way, it’s possible to never have to pay any taxes on the growth of the investment portfolios.”

All—100% of the wealthy entrepreneurs surveyed—said they were interested in ways to mitigate personal and corporate income taxes. “Many successful entrepreneurs can reduce their income taxes with qualified retirement plans,” says Homer Smith, Founder of Konvergent Wealth Partners, and co-author of Optimizing the Financial Lives of Clients: Harness the Power of an Accounting Firm’s Elite Wealth Management Practice, “The complication is that a large percentage of successful entrepreneurs only consider 401(K) plans where defined contribution plans would make more sense. With some defined benefit plans the amount of money the successful entrepreneur can contribute and thus reduce his or her taxable income tax bill is hundreds of thousands of dollars.”

Almost a quarter of the successful entrepreneurs are considering selling their companies with 88% of them looking for ways to eliminate or lower the capital gains taxes they would owe from the sale. According to Vince Annable, CEO and Founder of VFO Advisory Group and co-author of Your High-Performing Virtual Family Office: Maximizing Your Financial and Personal Lives, “There are several ways from using charitable trusts to installment sales to enable business owners to reduce the capital gains taxes they would otherwise owe when they sell their companies. While none of these tax minimization strategies are unique or proprietary, we find that many business owners are unaware of them and their advisors aren’t very familiar with them. This results in these business owners paying more taxes than they likely had to.”

Although tax mitigation is a major concern of successful entrepreneurs, relatively few of them are availing themselves of all the legally sanctioned ways to reduce their taxes. “Based on extensive studies of the ultra-wealthy, what’s very evident is that many of them are being poorly served,” says Justin Breen, the driving force behind the exclusive BrEpic Network and co-author of Superior Results: Maximizing the Value of Your High-Performing Family Office Just Like the Super-Rich, “Commonly the ultra-wealthy are getting financial advice, but the advice isn’t holistic or even customized to their unique situations. This is a function of the ultra-wealthy relying on professionals that are limited in their knowledge and capabilities or more interested in making a sale than delivering value. That’s why so many successful entrepreneurs are paying more taxes than are legally required.”

Russ Alan Prince is the executive director of Private Wealth magazine and chief content officer for High-Net-Worth Genius. He consults with family offices, the wealthy, fast-tracking entrepreneurs, and select professionals.