Glossary · Custody and data
Data portability is the ability to extract a firm's complete records — positions, transactions, history, documents — in usable form, at any time.
The question is not whether a provider permits an export but what the export contains and what it costs. A partial extract in an awkward format is a lock-in mechanism with better manners.
A platform that charges you to leave has told you something about how it intends to keep you.