The short answer

If you have a lump sum and won't need it for at least five years, history says investing it sooner has usually beaten waiting — because markets have risen more often than they've fallen, and every month in cash is a month without growth. Trying to time the market rarely works: the best days often come straight after the worst, and missing a handful of them can halve your returns. Regular monthly saving is the natural way to invest from income, and it smooths out the ups and downs by buying more when prices are low. For a large sum, a mixture — some invested now, some phased in over a few months, with near-term money kept in cash — gives most of the benefit of investing early while making a fall much easier to live with. Lawrence can help you build the right mix.

Two ways in: lump sum and regular saving

There are only two basic ways to get money into investments: all at once, or a bit at a time. Most people end up using both at different points in their lives, often without thinking of it in those terms.

Lump-sum investing

A lump sum is a single, large amount invested in one go. For South Africans in Thailand, it usually comes from one of a handful of places: the sale of a home in South Africa, an inheritance, a retirement fund payout, a business sale, a severance package, or savings that have built up in a bank account. The defining feature is that the money is already there — the only question is when to put it to work.

Regular saving

Regular saving means investing a fixed amount every month, usually from income: a salary, an annuity, rental income from a flat back home. It's how most people build wealth over a working life — and how most families save for children's school and university fees. The defining feature is that the money arrives over time, so investing it as it arrives is the natural thing to do.

Phasing: the in-between

There's a third option that sits between the two. If you have a lump sum but don't want to invest it all on one day, you can phase it in — sometimes called drip-feeding or cost averaging — by investing equal parts every month over, say, three, six or twelve months. You still have a lump sum, but you're investing it as if it were regular saving.

The real debate, then, is mostly about what to do with a lump sum: invest it now, or phase it in? And underneath that is the bigger question of whether anyone can successfully pick the moment.

Time in the market vs timing the market

"Timing the market" means trying to invest just before prices rise and sell just before they fall. It's an appealing idea, and it's what most people are really trying to do when they hold a lump sum in cash "until things settle down" — or until the rand recovers. The trouble is that it requires being right twice — when to get out and when to get back in — and almost nobody manages it consistently.

"Time in the market" means accepting that you can't predict the short term, getting invested, and staying invested so your money is working for as many years as possible. It sounds less clever. But over long periods it has been the far more reliable approach, for one simple reason: a large part of the market's long-term return comes from a small number of very good days, and they're almost impossible to see coming.

The best days hide next to the worst

J.P. Morgan's research on the US stock market over the twenty years from January 2005 to December 2024 makes the point vividly. $10,000 left fully invested grew to about $71,750 — around 10.4% a year. An investor who missed just the ten best days in those twenty years ended up with about $32,871 — around 6.1% a year, less than half as much. And seven of those ten best days came within two weeks of the ten worst days.

That last fact is the key. The best days usually arrive in the middle of a crisis, when markets are frightening and the instinct is to sell or stay out. The investor who panics after a bad day, or who waits on the sidelines "until things calm down", is very likely to miss the rebound that follows.

What missing the best days costs

$10,000 in the S&P 500, 3 January 2005 to 31 December 2024. J.P. Morgan analysis as reported by CNBC (7 April 2025). Seven of the ten best days fell within two weeks of the ten worst. Past performance is not a guide to the future.

The lesson isn't that markets always go up — they don't, and there will be painful falls. It's that the reward for investing comes to those who are there when it arrives. That's why the most important decision isn't the day you invest. It's making sure you invest, and then stay invested through the bad patches.

Lump sum or phase it in? What the research says

If time in the market matters most, it follows that money invested sooner should, on average, do better than money held back. That's exactly what the research finds.

In February 2023, Vanguard compared investing a lump sum immediately with splitting it into three parts invested a month apart. Using global share market data from 1976 to 2022, investing the lump sum straight away came out ahead 68% of the time. The results were strikingly similar across the markets it tested — 66.4% in the US and 67.5% in Australia, for example. And the longer the money was phased in, the more often the lump sum won — rising to around 70–74% when the phasing stretched to six months.

The reason is simple. Markets have risen in more months than they've fallen. So, on average, money waiting in cash to be invested misses out on growth. Phasing in only wins when the market falls during the phasing period — which happens, but less often than not. For South Africans, rand cash earns more than most — the repo rate was 7.25% in September 2026 — which narrows the cost of waiting a little, but doesn't remove it, and rand cash still carries the rand's own risk.

So why would anyone phase in?

Because "68% of the time" also means 32% of the time phasing did better — and if you're the person who invests R4 million the week before a 20% fall, an average doesn't feel like much comfort. Phasing in reduces regret. It means that if markets fall soon after you start, you'll be buying part of your investment at lower prices. For many people, that peace of mind is worth giving up a little expected return — especially if the alternative is being so nervous that they never invest at all.

The worst outcome of all is the one the research doesn't show: the lump sum that sits in a bank account for years because the owner is waiting for the perfect moment that never comes.

The four approaches compared

How the main ways of investing compare. There's no single right answer — the best choice depends on where the money comes from, when you'll need it and how you'd feel about a fall.

Lump sum win rate from Vanguard (February 2023). Whichever you choose, only invest money you won't need for at least five years.

The quiet power of regular saving

If the debate about lump sums is about getting money into the market sooner, regular saving is about something even more powerful: compounding over time. Small monthly amounts, invested for long enough, grow into very large sums — because the growth itself starts earning growth.

Take R10,000 a month, growing at 8% a year after charges — the level Lawrence's plans typically aim for:

• After 10 years you've paid in R1.2 million and it could be worth about R1.83 million.
• After 20 years you've paid in R2.4 million and it could be worth about R5.89 million.
• After 25 years you've paid in R3 million and it could be worth about R9.51 million.
• The growth overtakes your own money — after 25 years, more than two-thirds of the pot is growth.

That's why the single most valuable thing about regular saving is starting early. Every year you delay doesn't just cost you that year's contributions; it costs you the growth those contributions would have earned for every year that followed.

Rand-cost averaging: why falls can help the regular saver

Regular saving has another, less obvious advantage. Because you invest the same amount every month, you automatically buy more units when prices are low and fewer when they're high. Over time, that can mean your average cost per unit is lower than the average price over the same period. It's called rand-cost averaging (or simply cost averaging), and it turns market falls — which feel bad — into buying opportunities. The same idea works for currency: converting rand to dollars or baht a little each month smooths out the rand's swings.

Rand-cost averaging in action

R10,000 invested every month for six months into a fund whose price falls and then recovers. A simple illustration.

R60,000 buys 700 units at an average cost of R85.71 — below the R90 average price. At R120, they're worth R84,000. The same R60,000 invested in month 1 at R100 would buy 600 units, worth R72,000. In a steadily rising market, the lump sum would win instead.

Why a mixture is often the best way in

For most people with a large sum to invest, the choice isn't really "lump sum or phased". It's how to combine them. A well-built mixture captures most of the benefit of investing early while making the journey far easier to live with. A typical structure has four parts:

1. Keep near-term money in cash. Anything you'll need in the next couple of years — a condo deposit, school fees, a visa deposit, an emergency fund — stays out of the market entirely, in the currency you'll spend it in.
2. Invest a core amount now. Often a third to a half of the long-term money goes in straight away, so it's working from day one.
3. Phase in the rest. The remainder goes in over the next six to twelve months, in equal monthly steps. If markets fall, you're buying cheaper; if they rise, you've already got a large part invested.
4. Add regular saving on top. If you have spare income, a monthly plan keeps building the pot — and cost averaging keeps working for you.

The beauty of the mixture is that it removes the pressure to be right. You don't need to know whether markets — or the rand — will rise or fall next month. Whatever happens, part of your money benefits. That makes it much easier to stay invested — which, as the best-days research shows, is what really drives long-term returns.

Where to start

A plan for your lump sum or monthly saving, a better rate when the money needs to change currency, our number-one offshore account to hold money while you phase in, and a cheap route for regular transfers.

What's different for South Africans in Thailand

The lump-sum-versus-regular question is the same everywhere. But being a South African living in Thailand adds a few things to think about before you decide.

Your offshore allowance sets the pace

As a South African resident, you can move up to R2 million each calendar year offshore on your single discretionary allowance, and more with SARS approval through the foreign investment allowance — which can take three weeks or more. A large lump sum heading offshore may therefore be phased in whether you like it or not. Plan the investment timing and the allowance timing together, so money that's already offshore can go in straight away while the rest follows.

Currency comes first

If part of your lump sum will be spent in Thailand, decide how much needs to be in baht before you decide how to invest the rest. Near-term baht money shouldn't be invested at all. And if you're converting a large amount, the exchange rate matters as much as the investment timing: on R4 million, a one percentage point better rate is worth R40,000. A specialist can also phase a currency conversion, or set a target rate, in the same way you phase an investment. Our guide to cross-border investment considerations explains the currency side.

Tax timing

If you're Thai tax resident, foreign income earned from 2024 onwards that you bring into Thailand can be taxable. Where and when you invest a lump sum — and where the income from it ends up — can matter. Keep money from before 2024 separate, and take advice before bringing large sums in. If you're planning to cease South African tax residence, the timing of large investments can affect the deemed disposal on exit.

Beware of lump-sum "opportunities"

People with a fresh lump sum are a prime target for high-commission products and outright scams. If someone approaches you just after you've sold a house or received an inheritance, be very careful. A good plan never needs you to decide this week.

Regular saving for the big goals: education and retirement

Some of life's biggest costs are perfectly suited to regular saving, because they're years away and the money to pay for them arrives month by month.

School and university fees

Education is the clearest example. Fees for a young child won't be due for many years — long enough for a monthly plan to be invested for growth. Saving monthly for thirteen years with growth of 8% a year, more than 40% of the goal can come from investment returns rather than your own pocket. Lawrence specialises in education fee planning for expat families. Ask about school-fee planning, or compare schools in our international schools directory.

Retirement

For anyone still working, regular saving towards retirement — into a retirement fund or an investment plan — is the most reliable way to build an income that will last. For those already retired with a lump sum, the mixture approach above is often the best way to turn it into a portfolio that can provide income for decades. Our guide to investment time horizons shows how to match each part of your money to when you'll need it, and our guide to lump-sum investment planning covers the rest of the plan.

Two worked examples

Elize: a house sale of R5 million

Elize, 59, has just sold her house in Somerset West and is moving to Chiang Mai. She won't need most of the money for many years, but she's nervous: markets have had a good run and she's worried about investing at the top.

With Lawrence, she splits it four ways. R800,000 stays in cash — her visa deposit, an emergency fund and two years of spending, much of it converted to baht through a specialist. R1.6 million is moved offshore and invested straight away in a diversified global portfolio, using most of this year's discretionary allowance. R2.6 million is phased in over twelve months, about R217,000 a month, moved offshore partly on next year's allowance and partly with SARS approval, on a schedule set up in advance. And she sets aside a little of her living annuity income each month as regular saving on top.

If markets rise over the year, a large part of her long-term money was already invested. If they fall, her monthly instalments buy more cheaply. Either way, she's fully invested within a year — and she never has to guess the right day.

Jaco and Nok: R12,000 a month

Jaco, 38, works in Bangkok for a South African company; his wife Nok runs a small business. They have no lump sum, but can save about R12,000 a month. Their daughter is four. With Lawrence, they split it: R7,000 a month into an education plan for university in about fourteen years, and R5,000 a month into a long-term investment plan for themselves, both in hard currency. Both are invested for growth, and both benefit from cost averaging when markets — or the rand — wobble. They review it once a year, and increase it whenever their income rises.

The mistakes we see most often

1. Leaving a lump sum in cash for years while waiting for the "right moment" — or for the rand to recover.
2. Selling after a fall — and missing the best days that usually follow.
3. Pausing a phasing plan when markets drop, just when it's buying cheaply.
4. Investing money needed soon — the visa deposit, next year's fees, a condo deposit.
5. Converting a large sum at the bank's rate instead of a specialist's.
6. Forgetting the offshore allowance, so the phasing plan stalls waiting for approval.
7. Starting regular saving late, and losing years of compounding.
8. Buying from someone who called you just after you received a lump sum.

Questions to ask yourself

• When will I need this money — and is any of it needed in the next two years?
• Which currency will I spend it in?
• How would I feel if markets fell 20% the month after I invested?
• Would phasing in help me invest, rather than keep putting it off?
• How much can I move offshore this year, and when?
• Do I know the total yearly cost of what I'm investing in?

Keeping your money secure

Large transfers and new investment accounts attract fraudsters, especially around a house sale or inheritance. A few habits keep your money safe:

• Use a password manager and a different strong password for every account.
• Turn on two-factor sign-in on every bank and investment account.
• Use a private, protected connection on hotel, café and condo Wi-Fi.
• Confirm bank details by phone before sending any large sum.

How we researched this guide

We used Vanguard's research paper "Cost averaging: invest now or temporarily hold your cash?" (February 2023), J.P. Morgan's analysis of missing the best days in the S&P 500 from 2005 to 2024, as reported by CNBC (7 April 2025), South Africa's offshore allowance rules and the Reserve Bank's and Bank of Thailand's latest rate decisions. The growth illustrations use 8% a year after charges, the level Lawrence's plans typically aim for, 6% a year on rand cash and 1% on baht cash; they are illustrations, not forecasts. Checked 23 October 2026. Past performance is not a guide to the future, investment growth isn't guaranteed and values can fall as well as rise. This guide is general information, not personal financial advice.