Batch product update
For catalogs with a large amount of products, use the Import and Export features of Magento with expanded Inventory Management options to update sources and quantities by SKU.
To import updates, first export a CSV file for a specific or all sources. Edit the CSV file and add a row per SKU for each source and quantity. You need the source’s code when adding a new source and adding quantities of stock. You cannot add or update stocks using import-export features.