The payment startup based in Amsterdam has closed another round of funding, this time with a valuation of $2.3b. The round was completed by a single investor, Iconiq Capital. The amount raised in this round was not disclosed but it's assumed to be in the double-digit millions. Iconiq's LPs include Mark Zuckerberg, Sheryl Sandberg and Jack Dorsey. Last year, Adyen announced a $250m Series B that valued the company at $1.5 billion.