Great news. I think Brex has a great idea. But if anyone can, please do shed some light for me on how they grew so fast ? I mean, I can see how Bird etc would

Great news. I think Brex has a great idea. But if anyone can, please do shed some light for me on how they grew so fast ? I mean, I can see how Bird etc would achieve a 2B valuation fast, they're B2C so you can see them everywhere. Are they signing up thousands of customers at an astonishing rate or is this funding more related to potential growth ?