Bitcoin brokerage Circle Internet Financial is said to be raising as much as $40m in new funding.

As reported by Fortune, Circle is raising the funds at a valuation of $200m, citing persons with knowledge of the negotiations. A representative for Circle declined to comment.

The move, if confirmed, would represent Circle’s largest funding effort to date. Circle raised $17m in a Series B round last year, following an earlier $9m in Series A funding from 2013.

The funding would raise Circle’s total investment to $66m.