New "ROC" (Return of Capital) dividend activity sub-type

Broker API

Adds ROC (Return of Capital) as a dividend activity sub-type. Return of Capital events are reported under the DIV activity type with activity_sub_type set to ROC.

• The ActivitySubType schema now documents ROC alongside CDIV, SDIV, and SPD.
• The cash-dividend activity schema now covers both Cash Dividend and Return of Capital events, including share quantity entitled to the dividend or return of capital.
• Boolean flags on the cash dividend and substitute-payment activity schemas are now typed as strings constrained to true and false.

Affected Endpoints

• GET /v1/accounts/activities
• GET /v1/accounts/activities/{activity_type}
• GET /v2beta1/accounts/{account_id}/events/activities/{event_id}
• GET /v2beta1/events/activities