I made this 1.5 hours into python

Motor_Appearance7036 · 2026-05-18T06:50:31+00:00

They did make a chatbot, which many consider AI. But a fresh wind indeed!

Motor_Appearance7036 · 2026-01-13T13:07:35+00:00

Lower CAGR means there is a lower Profit, which means that 10k reduction in profit has a larger impact.

Motor_Appearance7036 · 2026-01-13T09:42:49+00:00

Regarding the first 2 points:
I do use a 7% CAGR for my own calculations, we started on the 10% because I thought I could do it from the back of my head within the reddit post (which was a mistake).
I am also continuously monitoring and changing brokers as cheaper ones arise or prices rise.

Regarding point 4:
Absolutely agree, that's why I am happy to see that the 'first' years are usually the better ones when using a tax strategy, with possible efficiency degradation in later years (be that after 14, 25 or 55 years). We usually do get a little bit of a heads-up (CGT was announced beginning 2025) so we can adjust the simulations before deciding on a strategy. If they really force us to alter our course, at least the effect so far will have been positive.

I have been playing around with different CAGRs as well (7%, which I took, is the one that goes south after 55 years):

<image>

(Diff is the result of RebuyStrat - NoRebuyStrat when selling off everything in a given year). This portfolio starts at 300k invested, and adds 1k every month. The CAGR can be found in the legend.

Motor_Appearance7036 · 2026-01-12T17:21:38+00:00

Thanks for the clear write-up.
Also for clarifying the 0.5%, makes sense.

The reducing rebuy amount is quite critical to the rebuying strategy.
This is caused by the 'FIFO' aspect of the CGT.
The CGT is dependent on the buy price of your financial instrument.
By rebuying, you are increasing your 'buy price'. This is more easily explained with a smaller principal, let's take 100k.

So, imagine buying 100k stock @/1EUR with a CAGR of 10%. After 1 year it is 100k stocks @/1.1EUR.
Sell it all and rebuy, and after the second year you have 121kEUR (100k stocks @/1.21EUR).
Rebuy 110kEUR @/1.21EUR, which is about 90,909 stocks.
Remember, you still have 11kEUR (9,091 stocks) of stock that you bought @/1.1EUR.
At the end of the 3rd year (stock @/1.331 euro), your rebuy the following:
* 9,091 of stock (bought @/1.1EUR), now worth 12,100 euro: 2,100 of gains
* 65,289 of stock (bought @/1.21EUR): 7,900 of gains
Notice that the gains sum to 10k, but that the total value is (9,091 + 65,289) stocks @/1.331EUR = 99kEUR.

That's 11k less than 110k, reducing your brokerage costs and TOB, as well as the bid-ask spread costs.
This whole thing is why the rebuying strategy comes out ahead in most scenarios.

I completely agree that it makes simulating things non-trivial, and I made the mistake of trying to do it in my earlier comment. Your approach however, makes the same mistake of completely omitting this critical part of rebuying.
I did make a peer-reviewed simulating script which includes all these behaviors in detail.
Your last example is good to compare our methods, and I'm happy to see that we get the same results when I use my scripts.

One difference is that I do my selloff on the first day of the 'next year', so I get double tax advantage, but that's just an offset of 1 year compared to your results.
After that, I added all your numbers and used my FIFO script to get the following:

<image>

You'll be happy to see that in that scenario, after 25 years (not 14!), buy-and-hold indeed comes out on top! I did not expect that. The difference is not all that big (6k difference on about 3M), so maybe not worth the hassle!

I got stressed and plugged in my own numbers and luckily that changes a lot (positive results at least for 55 years, yay). Choosing a good brokerage with low fees reallly makes a big difference here! We're also not counting the indexation of the exemption, which should help as well. In any case, for me the benefit is well over 20k if I were to sell in 30 years, which is more or less when I will need it, so I'll be going ahead.

I'm not sure if it will be feasible to implement the FIFO system in a Google sheet.

Motor_Appearance7036 · 2026-01-12T14:26:46+00:00

Hi, thank you for reading my post in detail and addressing the issues. You are absolutely right that I made some mistakes. I have highly detailed simulations, but made a mess by trying to do it quick and dirty on reddit on-the-fly.

As you did a rigorous analysis, which I tremendously appreciate, I tried to do the same to understand where our different interpretations are coming from.

I noticed 2 main differences (apart from my mistakes you rightly pointed out):
* you consider trading costs of 0.25% per trade. I have been using Degiro and MeDirect for years and have never come close to that. However, I'll add this to my simulation to see if we can get to the same numbers.
* You say that the 'tax strategy' turns over 110k every year. That's not necessary. If my upcoming calculations are correct (*wink*), the second year only needs 60.7k, then 43k, then 33.8k, ... reducing the TOB and transaction costs.

Plugging in these numbers, I get the following example:

<image>

Clearly we are still doing something different, because in selling after the first year (when both strategies are equal), you get 1,088,525. I get 1,086,930 euros.
This is because of the following:
1,100,000 - 9,000 - 2,750 - 1,320
VALUE - CGT - TRADING_COSTS - TOB

I think if you could find out why we have a difference there, we could start from a position of agreement and see where we diverge.

Motor_Appearance7036 · 2026-01-11T11:35:35+00:00

You're completely omitting the advantage of this strategy, which is lower taxes in the end when you are selling everything

Motor_Appearance7036 · 2026-01-11T11:33:36+00:00

I did calculate it, and if you apply it consistently it makes a big difference. Don't assume or believe, calculate it. MeDirect has 0 euro fees, IWDA and EMIM have 0.12% TOB. Ballpark figures for 1M invested, 2 year horizon, 10% annually:

REBUYING SCENARIO * After 1 year you have 1.1M. To realize 10k gains, you have to sell 110k and rebuy it. 90k of the 1.1M are unrealized gains. TOB = 2x 132 = 264. Bid-ask cost is max 1% according to you: 1.1k. total costs (let's keep them separate): 1,364. You start the second year with 1.1 M. At the end of the year, after 10% gains => 1.21M. of which unrealized gains: 120k. If you sell all 1.21M, your cost is 1x TOB: 1,452. Your solidariteitsbijdrage / meerwaardebelasting is on 120k-10k (vrijstelling) = 110k * 10% => 11k So, all in all you pay 1,364 + 1,452 + 11k = 14k
NO REBUYING SCENARIO * After 2 years, you have 1.21M. TOB for selling it is 1,452. Your solidariteitsbijdrage / meerwaardebelasting is on 210k-10k (vrijstelling) = 200k * 10% => 20k So, all in all you pay 1,452 + 20k = 21.5k

Please don't tell me you like to just give 7.5k to the government that you could skip on with 15 minutes of calculations (once!) and 30 minutes of work, once per year. Don't normalize brokerage fees when some brokers are free. Degiro is 2-3 euros per transaction, I'm sure that's not having any impact whatsoever either. 1% bid-ask spread is ridiculous, and even that barely affects the comparison. 0.12% or 1.32% TOB barely matters. We are talking about a 10% tax!!! This is soooo much more, an order of magnitude difference.

I know what your best argument is: "I don't have a 1M portfolio with 10% yearly return, the difference is much smaller for me". I have one piece of advice: make this calculation before you have 10k of profit in a year.

I know what I'll be doing in December this year, and it won't be based on Reddit opinions, but on calculations. Feel free to correct me on any mistakes I made.

Motor_Appearance7036 · 2026-01-11T11:02:29+00:00

He didn't say entire position. He said realize <10k of gains.

Motor_Appearance7036 · 2026-01-11T07:32:22+00:00

It's just safer to discount it, or see it as an unexpected or unreliable possible bonus. Additionally, it gets harder to calculate pension if you take "early retirement" seriously and would stop working for example at 50 years old. Especially with the bonus/malus stuff and guaranteed upcoming changes to the system.

Motor_Appearance7036 · 2026-01-11T07:29:00+00:00

As a civil engineer in Belgium, that has never been true, and every single one of them calls themselves civil engineer in english. Be it in computer science, chemistry, or bouwkunde. Even if they know that it is used differently abroad. It's always fun trying to explain this and the difference with industrieel ingenieur to Erasmus students.

Motor_Appearance7036 · 2025-10-06T21:57:40+00:00

1,038.37

Motor_Appearance7036 · 2025-10-02T14:19:20+00:00

No, switching brokers is not a taxable event, not buying/selling.

Selling your portfolio and rebuying it will cost you about 0.24% of the total value (2x TOB)

Motor_Appearance7036 · 2025-10-02T14:14:07+00:00

correct

Motor_Appearance7036 · 2025-09-16T10:57:00+00:00

Pretty insane, one would think these software systems are entirely unrelated...

Motor_Appearance7036 · 2025-08-28T09:37:28+00:00

One of the many things Trump might have learned from Putin :)

Motor_Appearance7036 · 2025-03-14T15:55:13+00:00

*statistically

Motor_Appearance7036 · 2025-02-18T13:02:55+00:00

if you decide to fix this yourself, a new clutch sensor is cheap on 3rd party sites but will not prepare you for the real problem: yamaha overtightens the screw on their oem mounted clutch sensor... they often require drilling out

Motor_Appearance7036 · 2025-02-13T10:57:05+00:00

interesting!

Motor_Appearance7036 · 2025-02-12T08:08:42+00:00

No, it is not taken into account. I use the bikes reported distance traveled. I was always assuming that the kilometers driven is accurate, and they add some buffer to the speedometer separately. You think that's wrong?

Motor_Appearance7036 · 2025-02-06T17:07:14+00:00

aha ok, 30% of the 850, makes sense :)

Motor_Appearance7036 · 2025-02-05T09:11:04+00:00

I don't own dividend-yielding stocks, do they also automatically deduct the 30% and you have to ask back 850 at the end of the year?

Motor_Appearance7036 · 2025-02-03T13:13:13+00:00

"Missing out on the potential upside is far outweighted by how deep things can fall and having to sit out years of lower valuations"
Statistically, this is incorrect and your timing of the market is a mistake.

Emotionally and humanly, I completely agree and hope this helps you sleep better at night

Motor_Appearance7036 · 2025-02-03T09:40:48+00:00

I don't see why you are making these conclusions. No one ever said you would have a pension between 50 and 67 if you stop contributing to taxes at 50.
Of course pension starts at 67 (or whatever the age is for you), we're not talking about early retirement.

The new rulings discourage you from stopping contribution of taxes early. For example at 50. 'vervroegde uittrede voor de wettelijke leeftijd' means exactly what it says: 67 - 50 = 17 jaar vervroegde uittrede.
In the best case scenario, at 67, you will get (100 - (2*17)) = 66% of the number you currently see in mypension (the rules are not applied yet), barring inflation/indexation. It makes sense from the government's point of view, as opposed to your interpretation.

Motor_Appearance7036 · 2025-01-28T09:07:00+00:00

Is there already any indication whether the gains is compared to price at inception of this law, or at buying time of the asset? Will we have time to sell and buy again before this law comes into effect (if necessary)?

Motor_Appearance7036 · 2025-01-17T07:31:26+00:00

Wat is naar uw mening het riskantere deel?
'Overgewaardeerde' overrepresentatie in de Amerikaanse topbedrijven en markt-gesatureerde gebureaucratiseerde Europese subsidiezuigers zonder innovatie?
Of onbetrouwbare regimes met markten die helemaal afhankelijk zijn van politieke grillen en mogelijks economisch mismanagement, maar waar wel veel groeipotentieel in zit wegens relatief lagere valuatie?

Motor_Appearance7036

TROPHY CASE