The Principal

Early in my career, I spent a couple of years building execution systems for a fund. Not the glamorous part of trading. The plumbing. When a portfolio manager decided to buy a few million shares of something, my code figured out how to actually get it done without moving the price.

The first thing they teach you on an execution desk isn't math. It's suspicion.

Every order you send goes through somebody else's hands. A broker. An exchange. A market maker. Each one is technically working for you, and each one is also running a business. The broker gets paid on volume. The market maker gets paid on the spread. The exchange gets paid on the flow. None of them are villains. All of them have a number they're trying to hit, and your number is only sometimes the same as theirs.

So we measured everything. Every fill against the price when we made the decision. Every route against every other route. Not because anyone was cheating, but because nobody would ever care about our outcome as much as we did. That gap between their incentives and ours had a cost, and if we didn't measure it, we paid it without knowing.

I think about that desk a lot. Because it turns out almost everyone's financial life runs the same way. We just don't call it an execution desk.

Economists have a name for this. The principal-agent problem.

The principal is the person whose interests are on the line. The agent is the person acting for them. The problem is that the agent has their own interests, knows things the principal doesn't, and does most of the work where the principal can't see it.

Adam Smith spotted this in 1776. Writing about the big joint-stock companies of his day, he pointed out that managers running other people's money couldn't be expected to watch over it with the same anxious care that owners watch over their own. Negligence and waste, he figured, would always creep in. Two hundred years later, Michael Jensen and William Meckling turned the idea into a formal theory and gave the cost a name: agency costs.

They broke it into three pieces, and I'd argue these three pieces quietly run your whole financial life.

Monitoring costs. What you spend watching the agent. Time, attention, audits, software.

Bonding costs. What the agent spends proving they're trustworthy. Licenses, guarantees, reputations, fiduciary oaths.

Residual loss. What's left over. The value that leaks out anyway, because no amount of monitoring or bonding ever lines up the incentives perfectly.

That third one is the killer. Residual loss doesn't show up on any statement. It's the money you never knew you could have had.

Once you see it, you can't unsee it.

The person who sold you your house was your agent. A famous study by Steven Levitt and Chad Syverson looked at homes that real estate agents sold for themselves versus homes they sold for clients. When it was their own house, they left it on the market about ten days longer and got a few percent more for it. Not because they're bad people. Because on a client's house, an extra 10,000 dollars in sale price might move the agent's personal cut by something like 150 bucks, and an extra few weeks of showings costs them a lot more than that. The incentive whispers "take the offer." On their own house, the incentive whispers "wait."

Your loan servicer is your agent. It gets paid to process accounts, not to find you the best repayment plan. When a deadline passes and somebody has to put you somewhere, it puts you wherever the rule says to put you. Nobody over there is plotting against you. They're following the manual.

Your employer's compensation committee is, in a sense, your agent too, at least on the question of what you get paid. It's managing a budget for the company, and its job is to spend that budget carefully. If it's going to argue for you, it needs you to give it something to argue with. Otherwise you get the average, because the average is what nobody has to defend.

The advisor paid by commission. The insurance broker paid by the carrier. The fund manager paid on assets rather than results. The default option in your retirement plan that somebody else chose for a workforce of thousands. Each one is an agent. Each one carries some residual loss.

And now we're adding a new kind of agent, one that doesn't take a commission or have a quarterly target, which makes it feel trustworthy. That's exactly why it's worth a closer look.

Software agents don't have selfish incentives. That's the pitch, and it's partly true.

What they have instead is a different version of the same problem. They optimize for what you said, not for what you meant. Ask for cheap eggs and you might get eggs delivered with a tip and a fee, because "find" and "buy" were close enough. And they can be talked to by people who aren't you. A web page can carry instructions written for the agent instead of for the human, and an obedient enough agent will follow them.

So the old problem doesn't go away. It changes shape. Human agents drift toward their own interests. Software agents drift toward their literal instructions and toward whoever else is talking to them. In both cases, the gap between what you wanted and what you got is a cost, and it's still yours.

That's the part I want to sit with this Sunday. Every system that acts on your behalf is a gift and a risk at the same time. The gift is reach. You can't do everything yourself, and the people who try stay small. The risk is that reach cuts both ways, and every handoff is a place where your interests can quietly leak.

Here's the line I keep coming back to.

You can hand off the work. You can't hand off the stake.

The servicer processes your loan, but you carry the balance. The committee sets your raise, but you live on the paycheck. The agent clicks buy, but the charge is on your card. Whatever happens, the outcome lands on the principal. Always.

Which means the job of anyone building wealth isn't to avoid agents. That's impossible, and honestly, it's a recipe for staying broke and exhausted. The job is to become a very good principal.

I think being a good principal comes down to four habits.

Write the mandate. Agents fail most often when nobody told them clearly what success looks like. Before anyone acts for you, whether it's a person or a piece of software, write down what they're allowed to do, what they're not allowed to do, and what a good result looks like. Execution desks don't send an order without a limit price. You shouldn't either.

Know how they're paid. Not to accuse anybody. Just to understand where the pull is. If you know your agent earns more when you buy more, or when you sign sooner, or when you pick the default, you can lean against that pull when it matters. One honest question, "How do you get paid on this?", has saved me more money than any spreadsheet.

Verify on a schedule. Trust, but measure. Not constantly, because monitoring costs are real and you can drown in them. Just on a rhythm. A monthly look at what your systems did. A yearly look at what your advisors did. A check every time a notice arrives that says something changed. The point isn't to catch someone. It's to catch drift before it compounds.

Keep the irreversible decisions. Delegate anything you can undo. Hold on to anything you can't. Picking a gift idea is reversible. Signing a ten year payment plan isn't. Restocking coffee is reversible. Handing someone your identity isn't. The more permanent the consequence, the closer to your own hands the decision should stay.

You don't need a theory to use this. You need a list.

Grab a notepad and write down every agent in your financial life. People and software both. The advisor. The accountant. The insurance broker. The mortgage and loan servicers. Your boss, on the narrow question of your pay. The robo-advisor. The bill pay service. The budgeting app with read access to every account you own. Any AI tool you've connected to an inbox or a card.

Most people get to fifteen or twenty before they run out. Almost nobody has ever seen the list in one place.

Next to each one, answer three questions.

What are they paid to do? Not what they say they do. What actually moves their income or their metrics. Commission, assets under management, volume, a flat fee, a budget target, or for software, whatever instruction you gave it last.

What happens to them if they're wrong? If the answer is "nothing," don't fire them over it. Just check their work yourself, because nobody else is going to.

When did I last verify? A date, not a feeling. If you can't remember, the honest answer is never.

You'll find a few agents you trust completely, and you'll be right to. You'll find a couple you've been paying for years without a single check. And you'll probably find one or two that you didn't realize were making decisions for you at all.

That last group is where the residual loss lives. Put one review on the calendar for each of them this month. Then put the whole list on a yearly reminder. It takes an evening, and it's the cheapest monitoring you'll ever buy.

There's a reason the word "principal" means two things in finance.

It's the person whose interests are on the line. And it's the original sum of money, the base that everything else grows from. Interest gets paid on it. Returns compound on top of it. It's the thing you protect so that it can keep working.

I don't think that's a coincidence of language. Your capacity to make decisions about your own life is your real principal. It's the base that everything else compounds on. Every time you let a default make a choice you should have made, every time you show up to a conversation after the decision's already been made, every time you hand over a card without a limit, you're spending a little of that principal. Usually it's small. That's what makes it dangerous. Small leaks are the ones nobody fixes.

And every time you take it back, by running the numbers yourself, by making your case before the meeting instead of after, by building the guardrails before you give anyone the keys, you're adding to it. That compounds too.

I spent years on an execution desk measuring the gap between what we wanted and what we got. The best traders I worked with weren't the ones who did everything themselves. They delegated constantly. They just never confused delegating with disappearing.

Use agents. Hire help. Automate everything that bores you. Build the systems that free up your time, because time is the only asset that never comes back.

Just remember whose name is on the account.

Delegate the work. Keep the principal.

See you Monday.

Alex Rivera, Wealth Architect at Wealth Grid