The AEX is the main stock index of the Amsterdam Stock Exchange in the Netherlands. It was founded in 1983 and consists of the 25 most relevant companies listed on the Amsterdam Stock Exchange.

This index reflects the performance of the Dutch market, it is weighted by market capitalization. This means that companies with a larger market capitalization have a more significant impact on the fluctuations of the index.

Several of the companies that are part of the AEX are leaders in their respective sectors and have a notable presence on the international stage, such as Royal Dutch Shell, Unilever, ASML and Philips, to name a few, many of which pay dividends.

How is the AEX value calculated?

The following mathematical formula is used to determine the daily value of the AEX stock index based on the capitalization of the companies that comprise it:

AEX(t) = AEX(t - 1) × Σ Capi(t) / [ Σ Capi(t - 1) ± J ]

As with the IBEX35, an adjustment coefficient J is used. This coefficient is intended to avoid distortions in the index due to financial events such as capital increases, share issues or mergers and acquisitions.

The daily capitalization of an AEX company is determined by multiplying the number of outstanding shares of that company by its daily closing price on the Amsterdam Stock Exchange.

By way of example: if on a given day the AEX closes at 600 points and the total capitalization of the 25 companies that comprise it is 300 billion euros, if on the following day that capitalization increases to 303 billion euros, the AEX index would close that day at:

AEX (specific day) = 600 x 303/300 = 606 basis points.