Would be nice to have an "excel" version of XIRR

[ragnarkurmwunder]

The problem

When having a continuous buy and sell system (like online trading) then the "principal" is meaningless. Spreadsheet XIRR is desired.

The solution

Implement a version that accepts a stream of transactions (positive and negative).

An alternative 1

Use composer require phpoffice/phpspreadsheet and the following code:

use \PhpOffice\PhpSpreadsheet\Calculation\Financial;
$xirr = Financial::XIRR($values, $dates, 0.1);

Note, that dates can have many formats. It does not accept epoch, however. But epoch/(24 * 60 * 60) works. Note, that phpoffice/phpspreadsheet is a fairly large package, and installing it only for XIRR, is a bit overkill. Note, that this package is maintained, and is well tested.

An alternative 2

There is a manually downloadable package that performs the desired XIRR: https://www.phpclasses.org/package/892-PHP-Financial-functions-with-the-Excel-function-names-.html But the downside is that one must register to download it manually, and from there on maintain it oneself.