American Express has contributed to a $19m funding round that follows the anti-fraud technology developer's $20m series B round in February this year.

US-based fraud protection technology provider Signifyd has picked up $19m in funding from investors including American Express Ventures, the corporate venturing subsidiary of payment processing firm American Express.

Venture capital firm Menlo Ventures and growth capital firm TriplePoint Capital also contributed to the round, which increased Sygnifyd’s total funding to more than $50m.

Founded in 2011, Signifyd has created a machine learning platform to protect online retailers from fraud through chargebacks. The company guarantees 100% efficiency and promises to cover…