The simplest strategy in personal finance—and the most misunderstood

Every month, on the same day, the same amount. You buy units of a fund or ETF, regardless of what the market is doing. If the market has risen, you buy at a higher price. If it has fallen, you buy at a lower price. And you do not think about it.

It sounds obvious. Too obvious to really work, you might think. Yet the Capital Accumulation Plan (PAC) is probably the single most effective strategy available to the average saver. Not because it is perfect—it is not. Not because it outperforms every alternative—it does not always. But because it is the only strategy that most people can actually follow for twenty years without harming themselves.

And in personal finance, the best strategy is not the theoretically optimal one. It is the one you can maintain.

The problem is that a cathedral of confusion has been built around the PAC. Some sell it as a product—it is not one. Some confuse it with a safe investment—none exists. Some think it is something the bank does for you—it can, but at a high cost. And some, after reading three articles, are convinced that the PAC is “inferior” to the PIC and therefore do not invest at all, leaving their money sitting in a current account.

That is a little like saying walking is inferior to running, and therefore staying on the sofa.

Why waiting for the “right moment” is a problem

The scene is always the same. A saver has set aside a few hundred euros a month. They read that the markets are at all-time highs. They decide to wait. The markets rise further. They wait longer. Then the markets fall by 10%. “There, I knew it—I’ll wait for them to fall further.” The markets recover. The saver is still standing aside, with money in a current account losing purchasing power at a rate of 2–3% a year.

This mechanism has a name: analysis paralysis. And it is why most Italians have an abnormally large share of their assets parked in current accounts and deposit accounts—approximately €1.8 trillion, according to data from the Bank of Italy—while their purchasing power erodes month after month.

The PAC solves this problem at its root. Not because it eliminates market risk—that remains. Not because it guarantees returns—nothing does. But because it takes the decision out of your head and turns it into an automatic process. And in finance, automatic processes work better than emotional decisions. Almost always.

How a Capital Accumulation Plan works

The mechanism: dollar-cost averaging

The principle is elementary. By investing a fixed amount at regular intervals—monthly or quarterly, with monthly contributions being the standard—you achieve a precise mathematical effect: you buy more units when prices are low and fewer units when prices are high.

The result? The average purchase price will always be lower than the arithmetic average of prices over the period. It is not magic; it is a weighted average based on quantities.

A practical example using €500 per month for four months:

Month	Unit price	Units purchased	Invested
January	€100	5.00	€500
February	€80	6.25	€500
March	€60	8.33	€500
April	€90	5.56	€500
Total	Arithmetic average: €82.50	25.14 units	€2,000

The effective average cost is €2,000 / 25.14 = €79.55 per unit. This is lower than the arithmetic average of €82.50. That is because, in the months when the price was low, the same €500 bought more units.

This is not an advantage guaranteed in every scenario—if the market rises steadily, you would have been better off investing everything immediately. But it is a volatility buffer that makes the investment experience psychologically sustainable. And psychological sustainability, over a 20–30-year horizon, is worth more than any mathematical optimisation.

PAC vs PIC: what the research says

Here comes the comparison everyone looks for: PAC—gradual investing—versus PIC, or Capital Investment Plan, meaning investing a lump sum all at once (lump sum investing).

Historical data is clear: the PIC beats the PAC approximately 67% of the time. A Vanguard study using data from 1926 to 2011 across three different markets—the US, UK and Australia—showed that investing everything immediately produces, on average, a 1.5–2.4% higher return after 12 months.

The reason is simple: markets tend to rise over the long term. Every day your money remains outside the market is a day of potential return lost. By definition, the PAC keeps part of the capital outside the market for longer.

But here is the point that the purists of financial optimisation systematically forget:

Criterion	PIC (lump sum)	PAC (gradual)
Expected return	Higher (~67% of the time)	Lower
Risk of incorrect timing	Maximum—all at one point	Diluted over time
Psychological impact of a -30% fall	Devastating—all capital exposed	Manageable—only units already invested
Probability of abandoning the plan	High after an initial crash	Low
Suitable for someone with a lump sum	Yes, statistically optimal	Yes, if they cannot sleep at night
Suitable for someone saving from their salary	No—they do not have the lump sum	Yes—it is the only realistic option

And the final point is decisive. Most Italian savers do not have €50,000 to invest tomorrow morning. They have a salary from which they can set aside €300, €500 or €1,000 a month. For these people, who make up the overwhelming majority, the PAC-versus-PIC comparison is purely academic. The PAC is not an alternative to the PIC: it is the only viable path.

The simulations: what it becomes in practice

Let us talk about real numbers. A €500-per-month PAC invested in a diversified global equity portfolio—such as the MSCI World, with an average historical gross return of around 7–8% per year—would produce:

Duration	Contributed	Value at 5% per year	Value at 7% per year
10 years	€60,000	€77,600	€86,500
20 years	€120,000	€205,500	€260,500
30 years	€180,000	€416,000	€610,000

At a 7% return, after 30 years you have contributed €180,000 and the portfolio is worth €610,000. The €430,000 difference was generated by compound interest—essentially, the engine that turns PAC discipline into real wealth.

The most important figure in the table is not the final number. It is the difference between 20 and 30 years. In the first 20 years, the value grows by approximately €260,000. In the following 10 years—one third of the time—it grows by a further €350,000. This is the exponential nature of compounding: slow at the beginning, explosive at the end. And anyone who stops after 15 years because they “are not seeing significant results” is cutting down the tree before it bears fruit.

The invisible cost: PACs in active funds versus PACs in ETFs

This is where the difference becomes a chasm. The same PAC, with the same amount and the same time horizon, produces radically different results depending on the instrument:

Instrument	Annual cost (TER)	Entry fees	Value after 30 years (€500/month, 7% gross)
Global ETF (e.g. VWCE)	0.22%	€0	~€595,000
Traditional active fund	2.00%	1–3% per contribution	~€380,000
Difference	1.78%	—	~€215,000

Two hundred and fifteen thousand euros. This is not a typographical error. It is the price you pay for the apparent convenience of a PAC built by a bank using actively managed funds. It is compounding in reverse: costs that compound year after year, consuming an ever-growing share of your returns.

And beware: the 2% annual cost does not include the entry fees that many bank PACs charge on every single contribution—typically 1–3%. This means that, of your €500 monthly contribution, €5–15 does not even reach the market. Every month. For 30 years.

The best ETFs for a PAC: the practical choice

For a long-term PAC focused on global equities, the most widely used options—and, in our view, the most sensible—are:

ETF	Index	TER	Size	ISIN
Vanguard FTSE All-World (VWCE)	FTSE All-World (~3,600 securities, 49 countries)	0.22%	€14B+	IE00BK5BQT80
iShares Core MSCI World (SWDA)	MSCI World (~1,400 securities, developed markets)	0.20%	€65B+	IE00B4L5Y983

The difference between VWCE and SWDA? VWCE also includes emerging markets—approximately 10% of the portfolio. SWDA is limited to developed countries. Both are accumulating ETFs, which is fundamental for a PAC because dividends are automatically reinvested without advance taxation and without having to remember to do it.

As explained in the guide to ETFs, choosing an accumulating ETF during the accumulation phase is not an aesthetic detail. It is pure tax efficiency: every dividend reinvested automatically benefits from compound interest without the tax authorities taking 26% of it prematurely.

So, concretely, what should you do?

The PAC is not a product. It is a strategy

First, a fundamental point that the financial industry is careful not to clarify: the PAC is not a financial product. It is not something you “buy” from a bank. It is an investment method, an accumulation strategy that you can apply with any instrument and on any platform.

When a bank offers you “our PAC”, it is doing two things at the same time: selling you a fund—with its costs—and selling you the automatic nature of periodic investing, which you could replicate yourself for free. The added value of the banking service is convenience. The price you pay for that convenience is, as we have seen, in the hundreds of thousands of euros over 30 years.

(If you want to find out how much you are paying for your investments, try Plannix’s new cost calculator.)

How to set up a DIY PAC with the main Italian brokers

The good news is that, in 2026, building an independent PAC is accessible to everyone. Here is how it works with the main brokers:

Directa SIM — The most widely used Italian broker for ETFs. It offers an automatic recurring purchase service for ETFs. Fixed execution fees, from €1.50 to €5 depending on the profile. No entry fee. A PAC can be configured on a monthly, bimonthly or quarterly schedule.

Fineco — A platform integrated with a current account. It offers “Replay”—an automatic ETF PAC with reduced fees (€2.95 per execution with one ETF). Convenient for those who want everything with a single institution. Pay attention to costs if you add many ETFs to the plan.

DEGIRO — Very low fees, in some cases zero for ETFs on the core list. It does not offer a native automatic PAC: you need to set a reminder and make the purchase manually every month. For anyone who does not trust their own discipline, this could be a problem.

The key concept: a DIY PAC requires 10 minutes a month. Log in to the broker, buy units of your ETF and close the account. You do not need to be a rocket scientist. You need to be consistent.

When to stop

A question that comes up often is: “When should I stop my PAC?”

The answer is brutally simple: when you have reached the goal for which you started it. Are you accumulating for retirement? Continue until retirement. Are you accumulating to buy a home in 10 years? Continue for 10 years—with an increasingly conservative asset allocation as you approach the deadline; see the guide to rebalancing.

You do not stop a PAC because “the market has fallen”. In fact, this is exactly when the PAC works best: you are buying more units at discounted prices. Stopping after a decline is like closing your umbrella because it is raining too hard.

You do not stop a PAC because “the market is at an all-time high”. The market spends most of its time at all-time highs—that is how a long-term upward trend works. If you had stopped investing every time the market reached a high, you would have missed most of the returns of the last 100 years.

How to adjust over time: as income grows, so does the PAC

A PAC is not static. As your income grows—through career progression, changing jobs or reducing expenses—it makes sense to increase the monthly contribution.

The practical rule is simple: every time you receive a pay rise, allocate at least 50% of the increase to increasing your PAC. If you go from €2,000 to €2,300 net per month, add €150 to the PAC. You will not feel it because you are not reducing your standard of living; you are simply preventing lifestyle inflation from consuming your pay rise.

The most boring strategy is the one that works

The PAC is not exciting. There is nothing particularly thrilling about buying units of the same ETF on the first day of every month for thirty years. And that is precisely the point.

As John Bogle wrote: “Investing should be boring. Excitement in the financial markets is a cost you are not billed for.”

The Capital Accumulation Plan is the practical translation of a principle we repeat at Plannix ad nauseam: financial products are the last thing to choose, not the first. First come the goals. Then the plan. Then the time horizon. And finally—only finally—the instrument and investment method. The PAC is a method. An extraordinarily effective one, provided you do not confuse it with a product to buy at the bank counter.

The best strategy is the one you can maintain. And the PAC is designed precisely for that.

If you want to understand how to integrate a PAC into your financial planning, access our free course.

FAQ

What is the minimum amount needed to start a PAC?
There is no universal minimum amount. Technically, with brokers such as Directa, you can buy even a single ETF unit—which for VWCE is worth approximately €120. The point is not the amount, but consistency. €100 a month for 20 years is better than €1,000 a month for six months and then nothing. Compound interest does not require large sums; it requires time and consistency.

Monthly or quarterly PAC: does it make a difference?
In terms of final returns, the difference is marginal—on the order of a few tenths of a percentage point over long horizons. Monthly contributions have the advantage of being more granular for dollar-cost averaging and naturally aligning with your salary. Quarterly contributions may make sense if transaction fees are fixed and significant: investing €1,500 every three months costs less in fees than investing €500 three times. In any case, the difference between monthly and quarterly contributions is infinitely less important than the difference between investing and not investing.

If I have a lump sum, is it better to invest it all immediately or use a PAC?
Research says PIC in 67% of cases. But research does not sleep in your place. If you have €50,000 to invest and the market crashes by 25% the following week, the PIC loses €12,500 in a few days. Can you avoid panic-selling? If the answer is yes, invest immediately. If the answer is “I don’t know” or “probably not”, divide the amount into 6–12 monthly instalments. The statistical cost of this caution is modest. The cost of selling in panic after a crash is enormous.

Does a PAC protect against losses?
No. A PAC is not protection against declines. If the market falls by 40%, your PAC also loses value. What the PAC does is mitigate the impact of timing—the risk of investing everything at the worst possible moment. Above all, during declines the PAC makes you buy more units at low prices, which will generate higher returns when the market recovers. But one condition is necessary: do not stop the plan. The PAC works only if you maintain it even—and especially—when it hurts.