The Top of Order Book API returns the current best bid and offer for a specified bond.
If the specified bond exists in our universe, you will receive a response with all available data regarding the best bid and best ask. For example, if there are only asks and no bids for a given bond, the response will contain data for the ask-related fields, while the bid-related fields will all be null. If there are neither bids nor asks, the response will contain null values for all ask and bid fields.
Moment will provide data on yields to maturity and yields to worst as available, however, Moment can not guarantee that these yields will be available for all bonds. If yields are not available, the response will contain null values for yield-related fields.
If the specified bond does not exist in our universe or is inactive, you will receive a not_found error. If the bond is not tradeable, you will receive a bad_request error.