Note: this API will be removed in future versions of the API.
Please use the corresponding account-based API in its place.
Get cost basis information for each of a user’s accounts. The cost basis information is identical to a request made against the accounts/gainloss call. This call should be used when information is required across multiple accounts, as opposed to making multiple account-based calls.
If you're developing using a paper trading account, change the hostname to https://sandbox.tradier.com