A reverse split (Swedish: sammanläggning) means several shares are merged into fewer. The number of shares decreases while the share capital is unchanged, so the quota value per share increases.
The opposite is a split, where shares are divided into more. A reverse split does not change owners' stake in the company, only the number of shares they hold. The decision is made by the general meeting and is recorded as a share ledger event in the share ledger.

A share split means each share is divided into several shares, without changing the total value.
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Quota value is a limited company's share capital divided by the number of shares.
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Share capital is the capital the shareholders contribute to a company in exchange for shares.
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Share ledger events are the changes to ownership and shares that are recorded in the share ledger.
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