For myself I'll just keep it simple - rebase everything back to MYR (retirement currency) and rebalance twice a year
I'd say it's negligible for popular index funds. I've never had problem getting orders filled by bidding +1 cent for IWDA (typically has 3 cents wide spread)

Can help me understand this expense/spread thingy...

I know lower expense is good... lower bid/ask spread is good...

For an individual say diy buying one-time market (ask price) and selling market (bid price) 5-10 yrs later... why would spread become so important? Also at peak hours spread should be quite small

My calculation was based on the closing price everyday. Closing price is the last transaction that took place that day. It can be at the bid or ask price. So it's fair.
I was using all of the samples. Imagine yourself buying the index everyday at the closing price with $10 for 9 years.
Then, what is your average return p.a.? Basically that's what I did for an S&P 500 tracked in US vs the one listed in London.

My findings show that US domiciled S&P 500 wins.

Meaning the benefit of lower expense ratio and lower tracking error exceeds the benefit of lower WHT.

However, I can still try to perform hypothesis testing to see whether the difference is significant or purely by chance.

1) Buying S&P 500 in Euro vs USD - aka buying the same asset using 2 different currencies.[/size]

ETF currency does not matter because it is the NAV of the asset which matters.
However, it does matter if the ETF managers hold cash. Almost all hold a small % of cash depending on the currency.

Furthermore, you should be more concerned about the exchange rate when you decide to liquidate, not when you buy.
As you average down, the currency fluctuations will cause you to buy more units when it depreciates and buy less when it appreciates.
In the long run, you will return to the 'average' exchange rate and it only matters when you sell.

When you sell, the exchange will decide whether you earn more or less. This is very important because it will decide whether your compounded return is higher or lower.
Because of exchange rate, you may make a gain 3% gain in USD terms but a 2% loss in MYR terms.

E.g. 1 USD : 4 MYR, you convert RM1000 into $250 to invest. (Just once, no dollar cost average)
1 year later, your $250 grew by 6% p.a. for 2 years to $280.90 [250 x 1.06^2]

You decide to liquidate, MYR appreciated against USD. 1 USD : 3.5 MYR.
You get back RM983.15 [$280.90 x 3.5]. You made a loss.

Why loss? You put in RM1000 and get back RM983.15.
Your return p.a. is -0.84% [(983.15/1000)^(1/2)-1].

Usually by a few % so it's best to liquidate when MYR is weak not when it is strong. Technically, you should buy more S&P 500 when MYR is strong not weak. 

If on the other hand, MYR depreciates when you liquidate and convert back:

Say, 1 USD : 4.5 MYR. Your investment after 2 years is still $280.90 remember? But when you convert back, you get RM1264.05 [$280.90 x 4.5]
Your return p.a. is 12.4% [(1264.05/1000)^(1/2)-1].

See now currency is more important when you liquidate?

You really shouldn't be. If you go to the airport and buy a box of chocolate and it costs GBP1 / USD1.3 / EUR1.15 it doesn't matter which currency you pay for it - in the end you end up with a box of chocolates, not GBP or USD or EUR.

questions about WHT, I got confused.

A Malaysian citizen buying Irish domiciled ETF, WHT is 15%.

What if,
a US citizen buying Irish domiciled ETF, is the WHT 15% or 30%?
A Japanese citizen buying Irish domiciled ETF, is the WHT 15% or 30%?

It's not citizenship but tax residency...and tax treaty or not

questions about WHT, I got confused.

A Malaysian citizen buying Irish domiciled ETF, WHT is 15%.

What if,
a US citizen buying Irish domiciled ETF, is the WHT 15% or 30%?

A Japanese citizen buying Irish domiciled ETF, is the WHT 15% or 30%?

Ya talking about hedging currency...futures/cfd/options are some methods

It's relevant when you invest substantial sum overseas... say usdmyr 4.2 drop to 3.1... its big % and big $

Should always keep an eye on it

Withholding Tax (WHT) is only applicable for US non-resident alien.
Withholding tax is cash which the resident company holds to pay to the government on your behalf.
If they fail to keep this cash before distributing profits to you, they will still be liable to pay to the government.

Hence, US citizen do not have to pay WHT but pay according to their usual tax rates. I believe they measure the % based on each person's income.
Just like Malaysia. When you file income tax, there is a section for dividends received. However, we do not pay dividend tax because currently, it's exempt.
In future, we may have to.
WHT 15%. If you look at my thread. The dividends are already 'priced in' into the share price. Hence, the ETF does not pay dividends out but the NAV increases, and thus the price of the ETF itself. But someone point out if I am wrong.

questions about WHT, I got confused.

A Malaysian citizen buying Irish domiciled ETF, WHT is 15%.

What if,
a US citizen buying Irish domiciled ETF, is the WHT 15% or 30%?
A Japanese citizen buying Irish domiciled ETF, is the WHT 15% or 30%?

Withholding Tax (WHT) is only applicable for US non-resident alien.
Withholding tax is cash which the resident company holds to pay to the government on your behalf.
If they fail to keep this cash before distributing profits to you, they will still be liable to pay to the government.

Hence, US citizen do not have to pay WHT but pay according to their usual tax rates. I believe they measure the % based on each person's income.
Just like Malaysia. When you file income tax, there is a section for dividends received. However, we do not pay dividend tax because currently, it's exempt.
In future, we may have to.
WHT 15%. If you look at my thread. The dividends are already 'priced in' into the share price. Hence, the ETF does not pay dividends out but the NAV increases, and thus the price of the ETF itself. But someone point out if I am wrong.

WHT is charged by the host country to non tax residency ppl... so if you get German shares dividend in Germany you pay Germany's WHT rate... US ppl hold Malaysian shares get dividend in Bursa they pay Malaysia's WHT.

WHT is charged by the host country to non tax residency ppl... so if you get German shares dividend in Germany you pay Germany's WHT rate... US ppl hold Malaysian shares get dividend in Bursa they pay Malaysia's WHT.

Isn't Malaysian securities dividend (other than REITs) taxed at corporate level (single tier dividend) instead?

e.g. Maybank gets taxed 24% by LHDN -> shareholder 0% by LHDN -> whichever tax bracket % you're in by IRS

Between choosing US domiciled or Irish domiciled, has anybody done research on estate taxes? I read somewhere US estate taxes pretty high. It would be sad if you buy and buy and buy and buy and hold US domiciled ETFs for long term. And one day accident happens, and estate tax comes in, US government takes 40% of your portfolio.

Yes, withdraw before you die.

Assets subject to US estate tax
Non-US domiciliaries are taxed only on the value of their US “situs” assets. US situs assets generally include real and tangible personal property located in the US, business assets located in the US, and stock of US corporations. The definition of US situs assets may be modified by an applicable estate and gift tax treaty.
An exemption of $60,000 is available against the value of assets includable in the US taxable estate of an individual who was not US domiciled. Maximum tax bracket, 40%

Isn't Malaysian securities dividend (other than REITs) taxed at corporate level (single tier dividend) instead?

e.g. Maybank gets taxed 24% by LHDN -> shareholder 0% by LHDN -> whichever tax bracket % you're in by IRS