"Yup," Ferrol agreed, and if his voice was a little too cheerful and anticipatory, well, he was a man who enjoyed his work. He wasn't all soft edges and knew how to bite back when he had to.
For just a brief second, Ferrol was shocked at the accuracy of what Brian had just pegged him for; it flashed, momentarily and fleetingly, in his eyes before it was masterfully hid. It was made easier by the fact that he realized Brian was firmly entrenched in the Muggle world and in fact might not know the magical aspects of Arithmancy.
"Precisely," Ferrol said. "At least, after a matter of course. Basically advanced mathematical probability, and the gift of being able to see or imagine probabilities."
And it was true enough, for he dealt a lot with just that, but magic and runes added to the chances of being right. "Gets me a lot of varied work, and I get to play with the stock market." He laughed, the sound like a child with a favorite toy.
He rarely talked work with anyone, as himself. He never went under his real name, for he knew it would get him ostracized and perhaps arrested. It was delightful, to do so, even in a basic way like this with a Muggle who didn't know the intricacies and delicacy it sometimes required.