At the end of June my company moved our website's ecommerce product pages to a subdomain. The site had previously be consolidated on www.company.com; to improve usability we migrated all ecommerce product pages to shop.company.com.
I just compared our rankings from July (after the move) to our rankings in June (before the move), and found that almost every ranking keyword had dropped. However, the pages which lost rankings are not related to the subdomain switch. (That is to say, only product pages were moved to the subdomain - www.company.com/product became shop.company.com/product. The pages that dropped in rankings include the homepage, the about page, etc., which were not moved to the "shop" subdomain.)
Could the migration of product pages to the subdomain be the cause of our loss in rankings, despite the fact that the pages which lost ranking were not moved to the subdomain?