Thanks @kzhao. Sorry for not being clear. I'm looking for a way to query "How much History does this Asset have?" without actually downloading the History at that time.

Example scenario: I get a list of Assets (stocks and/or ETFs) for some sector. I'd like to quickly prune the list, eliminating any Assets that don't have whatever I consider to be enough History. I.e., I don't want to waste the time downloading what won't be enough History for Assets that I won't consider further.

Thanks.