Asset allocation for the DIY investor: see your real mix first

Quick quiz. Right now, without opening anything, tell me what per cent of your money is in shares. Go on. I will wait. If you answered with a confident round number, I have bad news: you are almost certainly wrong, and the reason you are wrong is not that you are dim. It is that your asset allocation is real and your mental picture of it is fiction. The two have been drifting apart for years, quietly, while you weren’t looking.

This is the thing nobody tells DIY investors. You can read every book on the planet about the perfect split between shares, bonds, cash, crypto and whatever else. It does you precisely zero good if you cannot see the split you actually have. Asset allocation for DIY investors starts with one boring, unglamorous step that the industry would rather sell you a managed product to skip. Look at your real mix, across everything you own, in one place. Then, and only then, decide what you want it to be.

What asset allocation actually is

Strip away the jargon and asset allocation is just this: of all the money you have invested, how much sits in each kind of thing. So much in shares, so much in bonds, a bit in cash, a punt in crypto, a chunk in property if you swing that way. That is the whole idea. It is the single biggest lever you control, bigger than which clever stock you picked on a Tuesday, and most people never actually measure it.

Here is the catch. Allocation is a property of your WHOLE book, not of any one account. The pension does not know the taxable brokerage exists. The exchange has never met your cold wallet. Each pot can only show you its own little slice, so each one tells you a confident half-truth. The real number lives in the sum, and the sum is the one view nobody hands you for free.

Why your real allocation drifts from what you think

You did not set out to be 80 per cent in tech shares. Nobody does. It happens the way weeds happen, which is to say by default, while you are busy.

A few things conspire here. Winners grow, so the position you were proudest of quietly swells until it is a third of everything and your “diversified” book is really one big bet wearing a trench coat. Money goes in piecemeal: a bit to the pension here, a recurring buy there, a windfall parked in cash you forgot to deploy. And the accounts hide from each other, so you never see the totals stack up. Each statement looks fine on its own. The trouble is only visible when you put them side by side, which almost nobody does, because doing it by hand in a spreadsheet is the kind of chore that gets started in January and abandoned by February.

So your idea of your allocation freezes at whatever it was the last time you checked, while the actual thing keeps moving. That gap is not a character flaw. It is just what happens to any number you do not reconcile.

Seeing your true exposure across every account

The fix is almost insultingly simple, and it is the same one we bang on about for everything. Get the whole book into one place so you can read it. Nothing gets linked or scraped, and no robot signs in as you to guess at the totals. You enter it yourself, once, so the numbers come from a record you can actually check against your statements.

Once the entire book sits in one ledger, the allocation stops being a mystery and becomes a fact you can stare at. Strata reconciles the lot and works out the breakdown you would otherwise babysit in a spreadsheet forever. Break it by asset class and shares versus bonds versus crypto versus cash land as one clean set of weights. Break it by account and the pension’s contribution separates out from the taxable book’s. Then there is the per-position weight, where the holding that crept up on you over the years finally shows up at its real size.

That is the moment the penny drops for most people. The “balanced” book turns out to be lopsided. The “small” crypto punt is eight per cent. The cash you meant to invest has been sitting there doing nothing since last spring. This is not a telling-off. It is just the truth, finally out in the open, and you cannot manage a mix you cannot see. This is the same reconciled-book discipline we wrote about in keeping your reasoning honest over time: the book has to be trustworthy before anything you build on top of it means a thing.

Deciding your targets on purpose

Now comes the part that is genuinely yours, and here is who does what. Strata shows you the mix. It does not pick the mix. It will not quietly nudge you towards some house model portfolio, it will not rebalance you while you sleep, and it will never whisper a trade in your ear. That is by design, and it is the whole point. The reconciliation is the computer’s job. The policy is yours.

So set a policy. Decide, on purpose and in daylight, what you actually want. A target weight for shares, one for bonds, and some cash kept back for sleeping soundly. Write it down like a thesis, with a reason attached, so future-you knows why present-you chose it. Then hold your real allocation up against that target and see the gap. Maybe you rebalance. Maybe you just steer new money towards the underweight bits and let it drift back over time, which is the lazy and frankly excellent option. Maybe you look at the gap, shrug, and decide you are fine with it, which is also a perfectly good answer as long as it is a DECISION and not an accident.

The point is that you are now choosing. A target you set deliberately and check against a reconciled book beats a “strategy” that is really just the accumulated residue of every distracted buy you ever made. If you want a rhythm for this, treat it as a regular habit rather than a panic: the same spirit as a quarterly portfolio review, where you sit down, look at the real numbers, and adjust on purpose.

The boring truth about the whole thing

Asset allocation is not exotic, and it is not a product. It is arithmetic you have been avoiding because the inputs were scattered and the spreadsheet rotted. Get the inputs into one honest book, read the mix off it, set your targets like an adult and check back now and then. That is the entire discipline, and it will do more for your returns than any amount of stock-picking cleverness.

We are biased about how to do the first part, obviously. We think a book you typed and can reconcile beats one a robot scraped and might be quietly mangling, and if you want the longer argument for the spreadsheet-versus-app question, we made it over here. But the principle stands whatever tool you use: you cannot allocate what you cannot see. So go and see it. Put the whole book in one place and let your real mix introduce itself.

If you would rather not find out your allocation one frantic spreadsheet evening a year from now, you can build your portfolio and read your real mix off a single reconciled view, then set the targets yourself.