Do I make more money if I combine 2 VTI investments (me and my spouse) into one investment?

Question

Myself and my wife own some VTI ETF. I own more and she owns less. We are planning to make some additional monthly investments into VTI.

Question -- Which account should we put more VTI in, mine or spouse's? Mathematically, will we make more money overall if we invested more in the account that had a larger quantity of VTI to begin with? Or does it not matter?

What I wonder about this -- If you go to this website and try two variations (just change initial amount in both. Keep rest the same), you will find that the one with the higher investment amount, makes a much larger profit than the other.

Does that calculation apply to VTI (ETF stocks) as well?

Answer 1

Mathematically is just does not matter as compounding is a percentage increase. x*1.05 is the same as (y+z)*1.05 with x = y+z

In real life there might be some caveats to this however

• are there any fixed (amount) costs associated? These will eat more on a smaller account than on a larger one
• taxation
• splitting everything appropriately in case of a divorce

Answer 2

What I wonder about this -- If you go to this website and try two variations (just change initial amount in both. Keep rest the same), you will find that the one with the higher investment amount, makes a much larger profit than the other.

I made two variations:

1. the default numbers:

• 10K initial investment;
• 25 years;
• 5% return;
• $100 additional contributions;
• monthly;
• 2% inflation;
• 40% tax rate. The result is $64,189.

2. Lets assume that initial investment and monthly contribution was split in half.

• 5K initial investment;
• 25 years;
• 5% return;
• $50 additional contributions;
• monthly;
• 2% inflation;
• 40% tax rate.
• The result is $32,094

So if there are two accounts like #2, then the total will be:

 $32,094 + $32,094 = $64,188

That $1 difference is due to rounding.

When you said that you wanted to combine accounts I assume that the accounts can be combined. If they are retirement accounts the current balances might not be able to be combined.

There can be tax issues today that could make it expensive to combine the accounts, if capital gains taxes would be due.

Now if there are no tax issues, or retirement account rules. One way it could save money, is if the higher balance would allow you to invest in a fund with lower fees. It could also allow you to invest in a fund with a higher minimum.

Answer 3

Does not matter. That site is glitched somehow.

Where it matters is tax lots. A "tax lot" is a block of shares in a particular account that were bought at a particular time. You pay less capital-gains tax when you hold the investment more than 1 year. So you are better off selling "tax lots" that you bought more than 1 year ago. If that is on one account vs the other, then that matters.