DIY investing platforms vs having someone manage it for you

There's a Stocks and Shares ISA sitting in an app you rarely open. Or cash you've been meaning to invest for, if you're honest, about a year now. Either way, you're not alone – and doing nothing is its own decision, even if it doesn't feel like one.

This post looks at what actually changes when you move from picking your own investments to having someone manage them for you, and what the UK data says about outcomes, cost and time, rather than what the industry assumes you'll believe.

What's actually different between DIY investing and having someone manage it

The practical difference is who makes the decisions. On a DIY platform, you choose the funds and decide when to buy, sell or rebalance. With a managed portfolio, someone else does that for you, within a risk profile agreed at the start.

Both routes use the same regulated infrastructure and ISA and pension wrappers, often with overlapping fund ranges. The difference is not access to better investments. It is who does the ongoing work, and how closely that work is tied to the rest of your finances.

The DIY market has grown, but experience hasn't kept pace

DIY investing in the UK has grown fast, but much of that growth is untested by a serious downturn. The market reached £392 billion by the end of 2023, up 14% in a year, according to Boring Money's 2024 Online Investing Report, and a meaningful share of those investors have less than five years of experience.

That matters because the hardest part of DIY investing rarely shows up in year one. It shows up the first time markets fall sharply and you have to decide, alone, whether to hold your nerve.

What the numbers say about outcomes, not just fees

DIY investing is usually cheaper on paper, but cheaper doesn't always mean better off. The International Longevity Centre, working with Royal London, tracked people who took financial advice between 2001 and 2006 and found they were on average £47,706 better off ten years on than those who took no advice, according to Unbiased. Against a typical one-off advice fee of around £2,000, that's a return nearly 24 times the initial cost.

The gain didn't come from clever stock picking. It came from steadier decisions and avoiding the costly habit of buying high and selling low when markets get frightening, exactly the temptation a managed approach is designed to remove.

Why so few people get this kind of support

Only 8.6% of people in the UK received financial advice on their investments, pensions or retirement planning in the past year, according to the FCA's 2024 Financial Lives survey. The same survey found that 61% of people holding more than £10,000 in investible assets kept at least three-quarters of it in cash rather than invested.

That gap sits at the centre of this question. Most people aren't choosing DIY investing because they weighed it against the alternative and decided it suited them better. Many have simply never had easy access to anything else, or assumed advice was only for people with far more money than they have.

From Lucy, co-founder of Welleness

For a long time I ran my own investments the way a lot of working women do, in the gaps. A transfer here, a fund picked because someone mentioned it once, a login I'd open every few months and quietly hope for the best. It wasn't that I didn't care, it was that money was the thing that got pushed to the end of a very long list.

What changed my mind wasn't a return I read about somewhere. It was realising I had no idea whether what I was doing added up to anything, or whether I was quietly repeating the same mistakes because nobody had ever looked at the whole picture with me.

I still think DIY investing is a reasonable choice for some people. But most of us underestimate how much we're carrying alone, and how much lighter it feels to share that load with someone else.

What you can do now

Check your investment platform or workplace pension for when you last reviewed your asset allocation, not just your balance.

Work out roughly how much of your savings above your emergency fund is sitting in cash rather than invested, and how long it's been there.

If nobody has ever looked across your full financial picture, not just your investments, book Welleness's free financial health check to see where you stand before deciding what to change.

Frequently asked questions

Is a robo-adviser the same as having someone manage my investments?

Not quite. A robo-adviser uses a questionnaire to build a ready-made portfolio, but it doesn't look at your wider finances the way a fully managed service typically does.

Can I move from a DIY platform to a managed portfolio later?

Yes. ISAs and pensions can usually transfer between providers, keeping the tax wrapper intact, though it's worth checking for exit fees first.

Is a managed portfolio the same as full financial advice?

Not always. Some managed portfolios are execution-only, so you still make the final decisions, whereas full regulated advice looks at your entire financial situation.

Roughly what does a managed portfolio cost in the UK?

Costs vary by provider, but typically include a management fee plus underlying fund charges. Compare the total cost, not just the headline fee.

Here is what one Welleness member said after completing her financial health check.

"Before using Welleness I thought speaking to a financial adviser was only for people who earn like 200 grand, or people who'd inherited. Without Welleness I would probably be less informed, and I wouldn't be reaching the levels of what I think I'm going to achieve now that I've spoken to Lizzie." Emily, Welleness user

If this has made you wonder whether your current approach is working for you, our free financial health check takes less than five minutes and gives you a clear picture across six areas of your financial life. No judgement. No jargon. Just clarity.

This post is for informational purposes only and does not constitute financial advice. For guidance specific to your situation, speak to a regulated financial adviser.