Index Funds vs. ETFs: Which to Choose If You’re a Beginner

Investing for the first time can seem complicated, but it doesn’t have to be. One of the first questions that arises is whether to start with index funds or ETFs (Exchange Traded Funds).

Both products follow the philosophy of passive management (or indexed management), meaning they replicate major indices (examples: MSCI Europe, S&P 500, or MSCI World) to achieve the same results as the index, thanks to very low costs.

However, there are important differences worth knowing.

Before getting into them, let’s first look at what they have in common.

Similarities: both are the foundation of passive investing

In general, both index funds and ETFs:

• Replicate a reference index.
• Offer automatic diversification.
• Charge much lower fees than actively managed funds, which usually fail to outperform their benchmarks.
• Aim to achieve the market’s return, without trying to beat it.

Key differences between index funds and ETFs

1. How they are bought
   
   1. Index funds: you subscribe to units through financial institutions or specialized banks, and transactions are executed at the end of the day.
   2. ETFs: they trade on the stock exchange, like a share, and can be bought or sold during market hours. They can be more accessible and allow intraday trading.

2. Valuation and trading
   
   1. In an index fund, orders are executed at the net asset value (NAV) at the end of the day. Therefore, they don’t allow investors to take advantage of intraday strategies.
   2. In an ETF, the price fluctuates in real time, offering greater flexibility for more sophisticated investors.
      
3. Taxation
   
   1. In Spain, index funds allow investors to transfer from one fund to another without paying taxes until the final redemption. (This advantage only applies to Spanish tax residents who are individuals.)
   2. ETFs, on the other hand, are taxed when they are sold and don’t benefit from this tax advantage. Other, more complex tax optimization strategies may apply.

4. Costs and accessibility
   
   1. Both have low fees. ETFs sometimes have slightly lower management fees, but they may involve trading costs such as spreads or brokerage commissions. In principle, you must buy whole shares, although increasingly there are options to buy fractional shares.
   2. Index funds are becoming more competitive, especially if you have access to institutional-class funds (although these are usually not available to individual investors). They always allow purchases in decimals, making it possible to set up automatic or one-off contributions from very small amounts — ideal for beginners.

5. Availability
   

ETFs stand out for their wide range of options: they cover global indices, sectors, industries, commodities (such as gold), sustainable criteria (ISR/ESG), and even cryptocurrencies.

Index funds have also expanded their range and are more than sufficient to build well-diversified portfolios — including ESG versions — but their variety is still more limited than that of ETFs.

So, which should you choose if you’re just starting out?

For an individual investor resident in Spain, if your goal is to invest long term in a simple and tax-efficient way, index funds are generally the preferred choice.
The favorable tax treatment makes most Spanish residents choose them.

If, however, you want more control over your trades or exposure to specific markets or sectors, ETFs can be a great option — especially as part of a managed or more personalized portfolio, or to complement a main portfolio.

For a non-resident investor or a company, where the Spanish tax benefit doesn’t apply, ETFs offer greater versatility for more advanced investors.

Aspect	Index funds	ETFs
Buy/Sell	Through a manager or bank; executed at end-of-day (net asset value).	On the stock exchange, traded in real time; intraday trading.
Taxation (Spain)	Transfers between funds are tax-exempt until the final redemption (for individuals with tax residency in Spain).	Not transferable; tax-loss harvesting strategies like those used by inbestMe can be applied to optimize taxation.
Costs	Very low fees; no trading costs.	Very low fees; there may be spreads and buy/sell commissions.
Contributions	Automatic and fractional from small amounts.	Bought like “shares” (increasingly available as fractional shares).
Offering	Broad (includes SRI/ESG), but more limited than ETFs.	Very broad: indices, sectors, commodities (e.g., gold), thematic, SRI/ESG, even crypto.
Typical profile	Individual with tax residency in Spain, beginner seeking simplicity and tax efficiency.	Legal entity or investor (resident or non-resident) seeking greater versatility or customization in exposure.

In summary, for a beginner investor in Spain

Both vehicles are excellent and highly efficient options for indexed investing.

The key is to adapt them to your situation, profile, and goals.

If you are an individual investor with tax residence in Spain, an index fund is probably the best starting point.

At inbestMe, you can invest through portfolios of both index funds and ETFs, with the confidence that they are designed to optimize costs and diversification.

In index fund portfolios, tax optimization is achieved automatically through tax deferral.

In ETF portfolios, intelligent tax optimization helps achieve partial deferral.

They are also designed to achieve optimal returns. The average inbestMe investor (risk profile 7/10) achieves an average return of 6.5%, about 4.5 points above their benchmark.

In the long term, the returns of index fund and ETF portfolios are usually very similar, since both follow the same investment philosophy.
Even so, due to small differences in composition — for example, the inclusion of gold in ETF portfolios — there may be years when one performs better than the other.