'Do' and 'does' are both of those forms in the existing indefinite tense with the verb 'to do.' Which just one you can use will generally rely on the sentence's subject matter. Their usage is nearly similar, aside from 1 occasion where You should use 'do' instead of 'does.' https://financefeeds.com/deribit-and-signalplus-launch-300000-trading-competition-to-engage-retail-options-traders/