Compound interest in crowdlending: how it works and how to use reinvestment

In crowdlending, this effect can occur when the investor uses the interest and the capital recovered from certain loans to fund new transactions.

However, there is an important difference compared with other financial products: compound interest in crowdlending is not guaranteed. For it to work as in a mathematical simulation, it is necessary to be able to reinvest the money on a constant basis and to obtain a similar return throughout the entire period.

For this reason, in addition to understanding the formula, it is advisable to know which factors can accelerate or reduce the compounding effect.

What is compound interest?

Compound interest occurs when the returns obtained from an investment are added to the capital and generate returns again.

The difference compared with simple interest is that, with simple interest, interest is always calculated on the initial capital. With compound interest, the new interest also generates interest.

In simplified terms, this growth can be represented by the formula:

Final capital = Initial capital × (1 + return)ⁿ

Where

n represents the number of reinvestment periods.

The most important consequence is that growth is not linear. The longer the capital remains reinvested, the greater the compounding effect can be.

How does compound interest work in crowdlending?

In crowdlending, compound interest arises when the investor reinvests the returns obtained.

Suppose a person invests 1,000 euros and earns interest. If they withdraw that interest and use it for their expenses, the investment will continue to generate interest on the initial 1,000 euros.

However, if they reinvest the interest, the capital available for subsequent investments increases.

For example:

• Initial investment: €1,000.
• Interest generated: €80.
• Capital available for reinvestment: €1,080.

If those 1,080 euros are invested again and generate new interest, the second round of return is calculated on a larger amount.

This process can be repeated over time.

Simple interest vs. compound interest

The difference can be easily understood with an example.

Suppose an investment of 1,000 euros generating 8% per year.

With simple interest, each year 80 euros would be obtained on the initial capital:

Year Initial capital Interest Accumulated capital

1 1.000 € 80 € 1.080 €

2 1.000 € 80 € 1.160 €

3 1.000 € 80 € 1.240 €

4 1.000 € 80 € 1.320 €

5 1.000 € 80 € 1.400 €

With compound interest, the interest is reinvested:

Year Initial capital Interest Final capital

1 1.000 € 80 € 1.080 €

2 1.080 € 86,40 € 1.166,40 €

3 1.166,40 € 93,31 € 1.259,71 €

4 1.259,71 € 100,78 €

1.360,49 €

5 1.360,49 € 108,84 €

1.469,33 €

The difference after five years would be approximately 69 euros.

The amount may seem small over a short period, but the effect increases the longer the term.

What happens when you reinvest the interest periodically?

The reinvestment frequency also has an influence.

In a P2P loan, interest may be paid monthly, quarterly, annually or at maturity, depending on the terms of the transaction.

If interest is received periodically and can be reinvested quickly, the capital can be put back to work sooner.

For example, if an investor receives 50 euros in interest and leaves it uninvested for several months, those 50 euros generate no new interest during that period.

If, on the other hand, the investor can add it to a new investment, the compounding process begins again.

For this reason, compound interest does not depend solely on the advertised interest rate. It also depends on when the money is received and how long it remains reinvested.

The term is one of the most important factors

Compound interest requires time.

Two investors obtaining exactly the same annual return may end up with very different amounts if one maintains the strategy for five years and the other for fifteen.

This occurs because, as time passes, the interest previously generated is added to the capital and takes part in the following rounds of return.

In crowdlending, however, an additional variable must be introduced: each loan has a specific maturity.

When a loan ends, the investor needs to find another opportunity in order to continue with the reinvestment strategy.

If there is a period with no capital invested, the compounding effect slows down.

What happens if there are defaults?

This is one of the points that distinguishes a mathematical simulation from an actual investment.

A compound interest calculator may assume that all interest is paid on time and that all capital is reinvested immediately.

In crowdlending, that does not necessarily happen.

A loan may be subject to:

• Payment delays.
• Defaults.
• Recovery proceedings.
• Slower-than-expected principal repayments.
• Partial or total losses.

When any of these situations occurs, the capital available for reinvestment may be lower than expected.

Therefore, a theoretical return of 8% per year reinvested over ten years does not mean that the investor will necessarily obtain the result that a mathematical formula with a constant 8% would produce.

The actual return will depend on the performance of each investment.

Is it necessary to reinvest all interest?

Not necessarily.

Reinvestment may be a suitable strategy for an investor seeking to progressively increase the invested capital, but it is not an obligation.

It may also make sense to withdraw the interest and use it as a source of income.

The decision depends on the objective of the investment.

If you are seeking to accumulate capital

Reinvestment can enhance long-term growth because the interest becomes part of the productive capital.

If you are seeking to generate income

It may be more appropriate to withdraw the interest periodically and use it to cover expenses or other objectives.

In this case, the compounding effect on the withdrawn portion is forgone.

Therefore, compound interest is not necessarily better than receiving the interest. They are different strategies for different objectives.

AutoInvest and reinvestment: how can they be combined?

Automation can facilitate a strategy based on reinvestment.

On a platform offering AutoInvest tools, the investor can set certain criteria so that available capital is automatically allocated to new investments meeting those parameters.

This can be useful when the aim is to prevent interest and recovered principal from remaining uninvested for too long.

However, automation does not eliminate the need to monitor the portfolio.

The investor must continue to review aspects such as:

• The criteria used.
• The level of risk.
• Diversification.
• The terms.
• The accumulated exposure to certain borrowers.
• The return obtained.

Automation can facilitate the execution of a strategy, but it does not turn a risk investment into a guaranteed investment.

Which factors can reduce the compounding effect

In a real investment, there are several elements that can cause the result to be lower than that of a simulation.

1. Uninvested periods

If the money remains in cash for weeks or months, it stops generating a return during that period.

2. Defaults

A loss of capital directly reduces the amount that can be reinvested.

3. Delays

Even if the principal is eventually recovered, a prolonged delay reduces the time during which that money could have been generating new returns.

4. Differing returns

Not all investments offer the same interest rate. The return obtained in the future may be higher or lower than the initial one.

5. Taxes

Taxes reduce the money that can actually be reinvested if the investor must allocate part of the returns to meeting tax obligations.

6. Fees

The fees associated with certain transactions may also reduce the capital available for new investments.

For this reason, when calculating the potential growth of a portfolio, it is more prudent to use several scenarios instead of assuming a constant return.

A more realistic example

Consider an investor who starts with 5,000 euros and obtains a hypothetical gross return of 8% per year.

If this investor could reinvest all interest, had no losses, paid no costs or taxes and managed to maintain exactly that return, the capital would grow on a compound basis.

However, in a real portfolio there may be periods without investment, loans in arrears, differences between projects and other factors.

For example, if part of the capital remains uninvested for several months, the effective return of the portfolio will be lower than the theoretical 8%.

It is therefore preferable to interpret a compound interest simulation as a mathematical projection, not as a forecast of returns.

How long does compound interest need in order to make a difference?

There is no specific period after which the compounding effect begins to be significant.

It depends mainly on three variables:

1. Initial capital.

2. Return obtained. 3. Length of time over which reinvestment takes place.

Time is particularly relevant because the interest generated during the first years may subsequently become a significant part of the capital that continues to produce a return.

This explains why starting earlier may be of considerable importance even when the initial amounts are relatively small.

However, starting earlier does not mean that more risk than necessary should be taken on. Capital allocated to crowdlending should be money that the investor is able to keep invested for the corresponding term.

Common mistakes when calculating compound interest in P2P

Assuming that the return will be constant

8% per year over ten years is a mathematical assumption, not a guarantee.

Ignoring defaults

A P2P portfolio may experience losses that significantly reduce the final return.

Not taking uninvested money into account

If the interest or the recovered capital remains in cash, it does not take part in compounding during that period.

Confusing gross and net return

Taxes and costs may reduce the amount that can actually be reinvested.

Concentrating the portfolio too much

Seeking to maximise compound return should not lead to excessive concentration of capital in a small number of loans.

Diversification remains important because a significant loss may have a much greater impact on a concentrated portfolio.

Is it worth reinvesting interest in crowdlending?

It may make sense when the objective is to progressively increase the invested capital and the investor has a sufficient time horizon.

Reinvestment allows interest to become part of the capital and to generate new returns.

However, the decision must take into account the risk of the investment, the available liquidity and the investor's personal needs.

It would make no sense to automatically reinvest all the money if that capital will soon be needed to cover a major expense.

The strategy must be adapted to the financial objective, not the other way around.

Conclusion

Compound interest in crowdlending occurs when the interest and the recovered capital are reinvested in new operations, allowing the returns generated previously to take part in generating new returns.

Its potential depends mainly on the initial capital, the return obtained, time and the ability to keep the money invested.

However, crowdlending introduces factors that do not appear in a simple mathematical formula: defaults, delays, periods without investment, taxes, fees and variations in return.

For this reason, a compound interest simulation should be used as a tool to understand the effect of reinvestment, not as a promise of future returns.

For an investor, the key lies in finding a balance between reinvestment, diversification, risk control and time horizon. Compound interest can help

a portfolio grow, but it only works as expected when the capital can remain invested and the returns can be put back to work.

The content of this article is provided for informational and educational purposes only. It does not constitute investment, financial, tax, or legal advice. Peer-to-peer (P2P) lending and crowdlending investments carry a risk of partial or total loss of capital. Past performance does not predict future results. Liquidity on a secondary market is not guaranteed. Readers are encouraged to conduct their own research and consult qualified advisors before making any financial decisions. The availability of products and services may be restricted in certain jurisdictions.