Common Mistakes and How to Avoid Them

Chapter 11 of Running a Family Office Under $100M

The mistakes that destroy founder wealth are surprisingly predictable. That's the frustrating part. They're not exotic or unique to any individual. They happen repeatedly, to smart people, in patterns you can see coming—if you know what to look for.

We've covered specific pitfalls throughout this playbook. This chapter pulls together the most damaging patterns I see, the ones that cost founders real money and real peace of mind.

Building Before You Need It

This one shows up constantly. Founder has a successful exit—say, $12M in liquid capital. Feels like serious money. Wants to do things properly.

So they set up a multi-jurisdictional structure. Trust in one place, holding company in another, foundation somewhere else. Multiple entities, multiple advisors, multiple everything. Costs $80K to establish and $50K+ annually to maintain.

For what? At $12M, most of this complexity serves no purpose. The tax benefits don't materialise because the structure doesn't match the founder's actual residency and situation. Asset protection is theoretical because there's nothing to protect against. The estate planning benefits won't matter for decades.

They've bought infrastructure designed for $50M+ because someone sold them sophistication. Here's the reality: industry research suggests you need at least $50–100 million in assets before a single family office becomes economically viable. The J.P. Morgan 2024 Global Family Office Report found average annual operating costs of $3.2 million. For smaller family offices with $50–500 million in assets, the average is still $1.5 million annually.

At $12M, you're paying family office costs on wealth that doesn't justify them. The money spent on unnecessary structure is money not invested. $50K annually for 10 years, compounded at 7%, is over $700K. Real cost, zero benefit.

The fix is boring: match structure to actual need. At $12M with simple circumstances, you probably need a holding company, an operating company if you're active, and good estate documents. That's it. Add complexity as wealth and circumstances justify it. Not before.

Opposite Problem: Cash Paralysis

On the other end, founders who can't pull the trigger.

Exit happens. Cash lands. They're going to figure out the right approach, do proper diligence, and not rush into anything. Eighteen months later, $15M is still sitting in savings accounts earning 4%.

The caution is understandable. They've read about people who lost money rushing in. They want to get it right. Each time they're about to act, something gives them pause. Market seems high. That advisor didn't feel quite right. This fund has a fee structure they're not sure about.

The cost of waiting isn't as visible as the cost of a bad investment, but it's real. If that $15M could reasonably earn 8% invested versus 4% in cash, the gap is $600K per year. Two years of waiting costs' $1.2M in foregone returns.

Vanguard's research is clear on this: lump-sum investing outperforms dollar-cost averaging roughly 68% of the time over a one-year horizon. Morningstar's historical analysis is even more striking—since 1928, cash has beaten stocks only 31% of the time over any one-year period. Over 25-year periods? Cash has never outperformed equities. Not once.

I'm not saying rush. Chapter 10 was about the value of pacing. But there's a difference between deliberate pacing—deploying core over 6 months while you learn about alternatives—and paralysis disguised as prudence.

If you've been sitting in cash for over a year and still haven't made meaningful progress, something's stuck. Either you don't have the right advisors, or you're avoiding decisions, or the complexity feels overwhelming. Figure out which one and address it.

Fee Blindness

Most founders have no idea what they actually pay.

They know the headline fee on their wealth manager. They might know the expense ratio on their ETFs. But the all-in cost across everything? Almost nobody can answer that question.

The layers add up. Wealth manager charges 1%. The funds they put you in charge of another 0.75%. There are transaction costs, custody fees, and FX spreads. The PE fund has a 2% management fee plus a 20% carry. The structured product has embedded fees you've never seen itemised.

A founder I know sat down and actually calculated his total costs across everything. Came out to 2.3% annually on assets under management. On $20M, that's $460K per year. He was stunned. No single fee had seemed unreasonable. The aggregate was enormous.

Fee drag is punishing over time. CFA Institute research shows that a 1% difference in annual fees can reduce your final portfolio value by 20–30% over 30 years. A 2% fee scenario reduces final wealth by roughly 30% compared to a no-fee baseline. On $20M over 20 years at 7% gross return, the difference between 2.3% and 0.8% in fees translates to roughly $19 million in lost compounding.

Nineteen million dollars. Transferred to various intermediaries rather than compounding in your portfolio.

I'm not saying all fees are bad. Some things are worth paying for. Active PE management that delivers top-quartile returns justifies its fees. A wealth manager who genuinely adds value through planning, coordination, and behavioural coaching might be worth 1%.

What kills you is paying high fees for low value. Paying active management fees for closet index funds. Paying for services you don't use. Paying without even knowing what you pay.

Audit your fees. All of them. If you can't calculate your total annual cost within an hour, you don't understand what you're paying.

Illiquidity Creep

Each commitment seems manageable. Then you add them up.

The first PE fund—$500K commitment, called over three years. Fine, that's less than 5% of your portfolio. A second fund you heard about. Another $500K. Still fine. A direct deal through your network. $300K. A real estate syndication. $400K. Another PE fund, different strategy, good diversification. $500K. A venture fund your former co-founder is raising. $250K.

None of these individually is irresponsible. In total, you've committed $2.45M to illiquid investments, with capital calls expected over the next several years. Plus, whatever you've already funded that's locked up.

Then the market drops 30%. Your liquid portfolio goes from $15M to $10.5M. But your PE commitments remain. The capital calls keep coming. You don't have the cash. You're either scrambling for liquidity, defaulting on commitments, or selling liquid assets at the worst time to meet calls.

Or the opposite scenario: a great opportunity shows up. Perfect fit for your situation. But you can't take it because your liquidity is locked in commitments you're lukewarm about.

I've watched both happen. Smart founders who didn't track the aggregate, didn't stress-test against a downturn, didn't maintain enough liquid reserves.

The guideline that makes sense: keep 30–40% of your portfolio genuinely liquid at all times. Truly liquid—not 'liquid except for capital calls' or 'liquid unless markets drop.'

Before any new illiquid commitment, calculate your total illiquid exposure, including unfunded commitments. If it's pushing 60% or higher, think hard before adding more.

Advice You Took at a Party

Founders network with other wealthy people. Conferences, dinners, private gatherings. Conversations naturally turn to investments, structures, and strategies.

Someone impressive—real success, real wealth—shares what they're doing. Offshore structure here. Investment in that fund there. This tax strategy was set up by their advisor.

It sounds compelling. They're clearly smart. They've clearly done well. If it works for them, maybe it works for you.

Except it might not. Their residency is different. Their wealth level is different. Their risk tolerance, family situation, liquidity needs—all different. The strategy that's perfect for their circumstances could be wrong or even illegal for yours.

I've seen founders restructure their entire approach based on a conversation at a dinner. Sometimes it works out. Often it doesn't. The information was incomplete. The context wasn't transferable. The execution was flawed because the original advice was casual rather than comprehensive.

Treat peer advice as input, not instruction. 'My friend does X' is a prompt to ask your advisors whether X makes sense for you. It's not a reason to implement X.

And be especially wary of advice that comes with urgency. 'You need to do this before year-end.' 'There's a small window for this structure.' Maybe. Or maybe it's pressure that benefits someone other than you.

Keeping Everything in Your Head

This one kills families more than founders.

You know where everything is. The accounts, the entities, the investments, the documents, the relationships. It's all in your head, organised in a way that makes sense to you.

Then something happens. Suddenly, unexpectedly.

Your spouse is now trying to manage a financial life they weren't involved in. They don't know the accounts exist. They don't have access. They don't have relationships with advisors who might help them. They discover things months later. They miss obligations. They make mistakes because they're operating in the dark.

The research on this is sobering. The Williams Group conducted a 20-year study of 3,200 wealthy families and found that 70% lose their wealth by the second generation, 90% by the third. But here's what's striking: only 3% of those failures stem from poor investment management or bad financial advice. This connects directly to why protection is a core function. A full 60% are caused by communication breakdown and lack of trust within families.

The problem isn't usually the portfolio. It's the information gap.

A Penguin Analytics survey of 13,500 families across 29 countries found that 47% lack even basic succession planning. Cambridge Trust research shows that 52% of adult children don't know where their parents store estate planning documents. And according to a Trust & Will study, 46% of people named as executors weren't even aware they'd been chosen.

The fix is simple and tedious: document everything. Master list of accounts, entities, and investments. Access information. Key contacts. Update it annually. Store it where your executor or spouse can find it. Tell them it exists.

This isn't about distrust or morbidity. It's about not leaving the people you care about with an impossible puzzle at the worst possible time.

Mistakes Nobody Talks About

A few patterns that don't show up in most guides.

Optimising for taxes at the expense of everything else. Founders who won't sell an investment because of capital gains—even when selling is clearly right. Who structures for tax efficiency in ways that create operational nightmares. Who makes decisions based on tax tail wagging the dog? Taxes matter. They're not the only thing that matters.

Treating wealth like a scorecard. Chasing returns to hit some number that represents 'success.' Compared to other founders. Feeling behind when portfolios underperform in any period. Wealth is a tool. When it becomes an identity or a competition, decisions get distorted.

Not enjoying it. Founders who build enormous wealth and then live like they're poor because spending feels irresponsible. Who never takes the trip, buys the thing, or helps the person, because preservation becomes an end in itself. There's a balance between profligacy and miserliness. Many founders never find it.

Ignoring the relationship. Spouses who aren't involved, who don't understand the financial picture, who get presented with decisions rather than participating in them. This creates problems during life and a catastrophe after death. Wealth management should be a shared project where possible.

Common Thread

Most of these mistakes share a root cause: not thinking about wealth as a system.

The founder who overbuilds treats the structure as a standalone problem. The one with fee blindness treats each investment as independent. The one who over-commits to illiquids isn't looking at aggregate exposure.

The playbook approach I've laid out is systems thinking applied to wealth. Structure, treasury, portfolio, income, protection, governance—they connect. Decisions in one area affect others. The goal isn't optimising each piece in isolation but building something coherent.

The successful founders share a quality that's hard to name. Patience, maybe. Perspective. A willingness to think long-term while others rush. An understanding that wealth management is a decades-long project, not a problem to solve and move past. They demonstrate both deliberate action and strategic restraint. They built the system thoughtfully. They staff it with good people. They follow the governance they set up. They adjust as circumstances change.

And then they spend most of their time on other things. Family, interests, the next project, life. Wealth serves them rather than consuming them.

That's the goal. This playbook is a map to get there. The mistakes I've described are the potholes along the way. Now you know where they are.

Avoid them.

What Comes Next

You've read about the common mistakes. Where you go from here depends on where you are:

If you've just had an exit, start with The First 90 Days After Exit.

If exit is approaching, Pre-Exit Wealth Planning covers what to do now.

If you already have infrastructure, Auditing Your Existing Setup helps you evaluate it.

If everything feels like too much, Minimum Viable Setup gives you permission to keep it simple.

And if you want something to bookmark and return to, The One-Page Framework condenses everything.

Explore deeper into understanding the investment landscape and learn about post-exit founder wealth destruction and the $10M trap.

Previous: Implementation Principles

Next: The First 90 Days After Exit

Start from the beginning: Running a Family Office Under $100M