The following table summarizes the goodwill movements in the year:


(in millions)	Gross Cost
Opening balance at January 1, 2024	$	399.3
Adjustments		(3.4	)
Exchange effect		(3.6	)
Closing balance at September 30, 2024	$	392.3

In relation to the acquisition of QGP Química Geral S.A. (“QGP”) in December 2023, the fair value of the acquired net assets was revised in the second quarter of 2024. As a result of the remeasurement period adjustments, there was an increase of $3.4 million in the fair value of the net assets acquired, with a corresponding decrease to the acquired goodwill.

The measurement periods for the valuation of assets acquired and liabilities assumed ends as soon as information on the facts and circumstances that existed as of the acquisition dates becomes available but does not exceed twelve months. We completed our alignment of the accounting policies and fair value adjustments in the second quarter and are not expecting further changes at this time.

The exchange effect for the nine months ended September 30, 2024 was $3.6 million relating to our Performance Chemicals segment.