ISO 10383 codes are used to identify financial markets.
A CSV version of this database is available here: https://www.iso20022.org/sites/default/files/ISO10383_MIC/ISO10383_MIC.csv
It would be a good OpenRefine exercise to import this in Wikidata.
A property to store these codes in Wikidata has been created recently by User:Iwan.Aucamp. Other columns from the database can probably be imported too!