[FR/EN] Problem with Inaccurate Performance on Air Liquide (Adjusted Prices vs. Actual Purchase Price)

English
1

Hello everyone,
I use Portfolio Performance (I’m a beginner) to track my investments, but I’m encountering a major problem with Air Liquide stock (FR0000120073). I’m tearing my hair out.

The problem: The historical prices I retrieve are automatically adjusted. They already include past free share allocations.

Specifically:

  • If I enter a purchase made a few years ago at the actual price at the time (e.g., €124), the PP chart displays a much lower price for that same date (e.g., €90) because it has been adjusted by the source.

  • Result: PP calculates inaccurate performance because it compares my actual (high) purchase price to an artificially low historical price. The software seems to be processing the chart rather than the reality of my transaction.

If I try to add the “Share Split” or “Free Shares” operation, the performance is counted twice (once by the price, which has retroactively decreased, and once by the addition of the shares). I can’t get tracking that reflects reality (price, allocations, fractional shares, etc.).

My questions:

  1. How do you manage Air Liquide in PP to maintain accurate figures and precise performance year after year?

  2. Is there a reliable data source that provides actual (unadjusted) historical prices and works well with PP?

  3. Or is it necessary to manually adjust all historical purchase prices to match the adjusted Yahoo chart? This seems like a bad long-term solution: if the price adjusts automatically year after year, then the figures will also adjust after the allocation, skewing everything. If you manually adjust your purchase price today to match Yahoo or another provider, everything will be broken again during the next free allocation, shifting the entire history once more (repository conflict).

Thank you in advance for your help.

2

Hey Samok,

can you share a screenshot of the booking and a shot of the screen showing the 90 EUR?

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I think you have to adjust your price and the number of shares (from the buy) against Air Liquide (AI.PA) - Stock split history

4

I do not have Air Liquide myself, but some thought :

Enter your transactions PP as per how they were at the time.
You can also import the already adjusted historical prices.
You can do a stock split operation at their date. I believe a split 11:10 is what Air Liquide is doing.
During this stock split operation, you can :

  • select to which operation the stock split conversion applies (those before the split) : it will modify them
  • Unselect “Convert historical price”

Continue with next split
edit : I just checked, a stock split applies to all transactions. So in this case the transactions have to entered in PP in the correct order. All transactions before the first split, the split operation, the next transactions are added, second split etc.

When all is done, for the future next stock split, you can do the same but this time select the “convert historical price”.

More complex case :

  • The “rompu” case where you get cash because of fractional share : I am assuming after the stock split, you can do a sell of those fractional share. Ex: 307 shares, after the 11-10 stock split becomes 337.7 shares at the new adjusted price, you sell 0.7 shares in order to get what your receive in cash as “rompu” maybe ?.
  • In addition to the 11-10 usual split you can have the fidelity bonus. For this I am quite unsure. If it applies to all your shares, I guess a 111-100 split works instead of the 11-10, but if it applies only to some of your shares I am not sure.
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