For most investors, putting a large sum into the share market all at once feels risky, even reckless. That is why many prefer to drip-feed money into the market over time. But is that caution reducing risk, or simply creating a different kind of cost?
My view on this has changed
When investing large sums into share markets, I have generally preferred to invest in stages rather than all at once. The main reason is to spread timing risk and preserve the option to invest more if markets fall.
Of course, this approach means that if markets rise steadily during that period, some returns are left on the table. But over the long term, I did not think that difference was likely to be material. And, to me, it felt like a sensible way to balance risk.
That said, over the past few years I have softened my view. Partly because it reflects a better understanding of the evidence supporting lump sum investing. But it also highlights a broader point: deciding when to invest is only part of the equation. The other part is how the money is invested.
Both how and what you are investing in, and timing need to be weighed when deciding whether to invest a lump sum immediately or stagger money into the market over several months.
What does the long-term evidence tell us?
There are a handful of seminal studies on lump sum investing that are worth acknowledging.
One of the most cited was published by Vanguard in February 2023. It examined 46 years of market data, through to 2022, and found that lump sum investing outperformed a staged approach 68% of the time. The logic is straightforward: a staged approach carries a higher opportunity cost because part of the money remains out of the market for longer, reducing the chance to capture market returns.
Another noteworthy study was published by PWL Capital in June 2020. It examined several share markets, including the United States, the United Kingdom, Japan, Germany, Canada, and Australia, using between 50 and 95 years of historical data depending on the market.
Its findings broadly aligned with Vanguard’s. Around two-thirds of the time, lump sum investing produced a better return than a staged approach, defined as investing the lump sum progressively over 12 months. PWL also estimated that the cost of staging money into the market was between 0.3% to 0.4% p.a. over the rolling 10-year periods analysed. In other words, that is the price of delaying full exposure to the market.
What makes the study particularly interesting is that it also examined tougher market conditions, including what happens when markets fall soon after investing. You might expect that after a 20% bear market decline, a staged approach would clearly come out ahead. But in most markets, that still was not the case. Even after a 20% fall, lump sum investing produced a better outcome around 54% of the time.
The same pattern held in expensive markets. When shares were trading in the 95th percentile of historic valuations, lump sum investing still produced a superior outcome 63% of the time.
The final insight worth sharing, although not a formal research paper like the 2 previous, was produced by Australian active manager Ophir Asset Management. It analysed 50 years of Australian market data from 1975 to 2025 and compared investing a lump sum at the start of each year with spreading that same investment evenly across four quarters.
Its conclusion was also clear: lump sum investing produced the higher return. Over the 50-year period studied, staged market entry delivered an average return of 11.3%, compared with 14% for a lump sum approach.
Interestingly, Ophir’s findings differed from PWL’s in one respect. In the Australian market, staged investing did appear to produce better results during bear markets. However, lump sum investing outperformed by a much wider margin during bull markets, which more than offset that benefit.
It is important to note that these studies generally found lump sum investing comes with higher short-term volatility than staged investing. In the period immediately after investing, returns can fluctuate more because the full amount is exposed to market movements from day one.
However, for investors focused on maximising long-term returns rather than minimising short-term volatility, the evidence still favours lump sum investing. In other words, the price of pursuing the higher expected return is accepting a bumpier ride early on.
Why lump-sum investing produces a better result?
The reason lump sum investing often produces a better outcome is that a large share of market returns tends to come in a relatively small number of trading days.
Research produced by Dimensional covering the 33-year period from 1990 to 2023 found that missing just the best 25 days would have reduced returns by almost half compared with staying fully invested throughout the entire period, as the chart below illustrates. Fidelity has also developed an interactive tool that lets you see the impact of missing the best 10, 20, 30 or 40 days across different markets since 2003.
One important caveat is that these studies generally assume the money waiting to be invested is earning little or no return. But in the real world, that cash is often sitting in a mortgage offset, investment loan offset or high-interest savings account. That changes the trade-off. Cash in a mortgage offset, for example, is already earning a guaranteed after-tax return equal to the home loan rate. Therefore, the decision is not simply whether lump sum investing beats staging. It is also whether the expected return from investing is compelling enough to justify giving up the return the cash is already producing.
The problem, of course, is that no one knows when those best days will occur. You must be invested to benefit from them. That is why the adage still holds true: it is time in the market, not timing the market, that matters most. And a staged approach is just “timing the market” in disguise.
Why staged investing seems more appealing
Staged investing is often more appealing because it feels safer. Prospect theory, developed by Kahneman and Tversky, suggests that investors experience the pain of losses roughly twice as intensely as the pleasure of gains. That makes loss aversion a powerful force in investment decision-making. Most investors fear investing a large lump sum, only to see the market fall 20% or more shortly afterwards. The return is one thing, but it is the regret that is harder to live with.
There is also a second psychological factor at play: confidence. When investing a large amount of money, it is important to think carefully about how it is invested, because that decision will shape the level of risk, as I will discuss below. For people with limited knowledge or experience, especially when it comes to investing large sums, that can feel overwhelming.
Debt recycling strategy benefits are often misstated
Debt recycling is a strategy that has become popular on social media. The basic idea is straightforward: use the equity in your home to establish an investment loan, progressively invest that borrowed money into the share market, and at the same time focus on repaying your home loan as quickly as possible. Often, proponents of this strategy suggest it helps accelerate the repayment of your home loan.
The problem is that this strategy does not magically help you repay your home loan faster. A recent study by the London School of Economics reinforces that point. In the form I have described, debt recycling will usually reduce a person’s ability to accelerate home loan repayments because it creates negative cash flow. In most cases, the interest cost on the investment loan will exceed the dividend income generated by the shares. That shortfall reduces free cash flow, which in turn reduces the amount available to pay down the home loan.
That said, debt recycling can still be attractive for households with very strong surplus cash flow. Take an investor with $10,000 a month of surplus cash flow. One option would be to direct $5,000 towards the home loan and invest the other $5,000 into the share market. But a more effective structure may be to direct the full $10,000 towards repaying the home loan, while funding the share investments by borrowing $10,000 a month against the equity in the home. Yes, this still creates some negative cash flow, but the drag will be relatively minor compared to the total surplus cash flow.
Using the logic behind lump sum investing, an even stronger approach may be to borrow a larger amount upfront, say $500,000, against the equity in the home and invest it immediately into the share market. I estimate the after-tax cost of servicing that debt, net of dividends, could be around $11,000 a year. That would still leave roughly $109,000 a year available to accelerate repayment of the home loan.
This is why debt recycling should not be seen as a strategy that automatically helps repay your home loan faster. It only improves home loan repayment if the income from the investment exceeds the interest cost on the recycled debt, which is unlikely when the share portfolio is fully or 100% geared. In that scenario, the strategy is not really accelerating debt reduction on its own. It is better understood as a cash flow, tax and structuring strategy that can make sense when someone already has enough surplus cash flow to both service the investment debt and aggressively pay down their home loan.
Enhanced dollar cost averaging if it makes you feel better
It is entirely possible to accept the evidence behind lump sum investing and recognise that, mathematically, it is the superior approach yet still feel uncomfortable investing a large amount all at once. And that is perfectly reasonable. People tend to stick with what they are comfortable with, and financial decisions are not always about maximising the absolute highest return.
An alternative worth considering is enhanced dollar cost averaging, rather than standard staged investing. This approach was first outlined in 2011 by Lee M. Dunham and Geoffrey C. Friesen. The idea is simple: instead of investing the same amount each month, you vary the amount depending on whether the market has risen or fallen.
For example, rather than investing a flat $1,000 each month, you might invest $2,000 if the market has fallen since the previous month, and only $500 if the market has risen. The exact amounts can be tailored to suit your circumstances, but the principle remains the same: invest less when markets are rising and more when markets have pulled back.
This approach may appeal to investors who understand that lump sum investing offers the best expected outcome but still want a process that feels more measured and emotionally manageable.
How you invest depends on what you’re investing in
The extent to which you lean towards lump sum investing should depend, in part, on how compelling your investment thesis is for the markets, sub-asset classes and index methodologies you are considering.
For example, if you are looking at the US Nasdaq and accept that it is trading on a forward P/E of almost 26 times, which is very high relative to its long-term history, then a staged investing approach may be more appropriate. In that case, valuation risk is elevated, so easing into the market may make more sense.
By contrast, if you are considering the UK market (FTSE 100 index), trading on a forward P/E of less than 14 times, or an emerging markets index, where some markets are trading on forward P/Es as low as 11.3 times, you may feel more confident investing a larger lump sum. Those markets appear cheaper by historical standards, which can strengthen the case for being more aggressive.
In my view, how you invest should be shaped by what you are investing in. Perhaps the strongest combination of evidence-based thinking is to identify the most attractive markets first, then apply a bias towards lump sum investing. Those two approaches together are likely to produce the best outcomes.
Staged investing should be the fallback, not the default, and mainly reserved for situations where the investment opportunity is less compelling.
