What's the difference between the S&P 500 ETFs?

Hi I noticed there are s&p 500 shares available on the app and one is around £20 more then the other. I just wondered what the difference between then was. I am still new to this all and trying to figure it all out so I am sorry in advance if it is a stupid question.

Thank you.



It’s not a stupid question at all, in fact, you’re not the first person to ask it. I’ve moved it to back to it’s own topic now though as I can’t find the topic where it was discussed before :thinking:

sorry @Certi.Curti for cutting you off there


Its not a silly question.

One is provided by Vanguard, the other by iShares - Simply put they’re two separate organisations tracking the S&P 500. The difference in share price isn’t a factor worth looking at - the key thing is to look at historical performance - how well they track the index, and fees (known as expense ratio)

In the case of these two, they’re both 0.07% and their performance have been pretty identical. iShares marginally better in the last year by decimals.

Its a question of whether you think one will track the performance of the S&P better than the other going forward. I hold iShares - this may change in the future depending on performance.


LOL I was thinking what just happened there…

Don’t you sleep? Alex lol.


Alex is always on the prowl


Thank you all so much. The support within this community always amazes me.



Just adding to the very good answer by Certi.Curti, specifically for IUSA and VUSA, probably one of the main differences is the way that they track the index.

The former uses what we call Optimized sampling, while the latter uses Full replication.

You can see the difference here


The bottom line is that full replication buys all the securities in the index, while optimized sampling uses statistical metrics in order to choose some of them.


Would it be possible for Freetrade to add the OCF to the ‘About’ Section when you’re looking at the ETF? To me, that’s the most important thing to check. It would save me having to open the Key Information Document, which can sometimes be a pain to do on mobile. But I guess it would then be a problem of keeping it up to date…


Hi @Gaz92 (and @jazzersi) it’s a really good idea, and the primary way I filter funds.

If you add your vote to the idea right here the sheer weight of numbers will hopefully help FT prioritise it :slight_smile:


Can someone shed any light on the difference between these two ETFs that track the same index? Vanguard is double the price and appears so for many funds they offer.
Many thanks.

The price per share is meaningless and arbitrary. If you spend the same amount on either, you’ll end up invested in about the same amount of the underlying 500 companies.

Normally the main thing that would seperate 2 ETFs tracking the same index would be their OFC, but they both have the same OFC of 0.07%. So you might expect their performance to be identical.

But one more thing separates index ETFs: tracking error, or how closely they manage to track the performance of their index. I don’t have a good source that gives a figure for this; does anyone else?

But comparing their annualised performance over ytd, 3 and 5 years via Morningstar, VUSA seems to be slightly better than IUSA, suggesting consistently lower tracking error.



There are few material differences between the two. As @anon287192 says, its important to understand that a higher unit cost does not make VUSA more expensive.

You can use JustETF to compare the two. iShares ETFs tend to have a slightly higher spread. However, the lower unit cost of IUSA could allow you to keep more of your money invested.


I’ve moved this thread over to keep all of the info about the differences between these ETFs in one place.

There’s some more details earlier in the threads, I hope that helps!

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@anon287192 @christopher excellent advice as always fellas. I tend to look at the price as I feel I will get more for my money knowing I don’t have huge amounts to invest. Acknowledge that this is not always the case and so expert opinion is much appreciated :+1:t2:

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Good call on justETF. Excellent resource :+1:t2:
I like the strategy builder part of the site, it has streamlined my focus on 2 ETF’s I intend to buy

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I bet they are not available on Freetrade yet though?

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Your right the ones it suggested aren’t on Freetrade yet but I researched a couple that are. I used the same strategy, asset allocation and it came out with better forecast returns :+1:t2:



I noticed Freetrade has a couple of S&P ETFs, specifically Shares like £VUSA and £IUSA.

I understand that these ETFs track the top 500 companies in the USA, so my question is why is the price of these ETFs so varied?

If these funds have investments in the same 500 companies, I don’t see why I would invest in a more expensive one (£VUSA) which is double the price of £IUSA - HL has S&P ETFs (SPY5) which is trading at 10x the price of £IUSA.

My assumption is that the holdings in the 500 companies are varied, with some ETFs holding more in these 500 companies, but I would have thought that the relative growth and price increases (or decreases) of these ETFs are going to be fairly similar?

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Relating to this, can someone compare the dividends for IUSA and VUSA for me please as I cannot find anything on this subject myself