Coinbase is the one of the largest digital currency exchanges in the world. We store about $1B of digital currency (bitcoin, litecoin, ether) on behalf of our users. Given the instant nature of digital currency and that it can't be reversed, we have one of the hardest payment fraud and security problems in the world. We are hit by the most sophisticated scammers constantly and consequently we are at the forefront of the fight against fraudsters and hackers. We've witnessed and solved loopholes exploited by fraudsters years ahead of the broader industry (e.g., vulnerabilities in second-factor tokens delivered by SMS, phone porting attacks, loopholes in online identity verification, etc.). I'll talk about our risk program that relies on machine learning (supervised and unsupervised), rules-based systems as well as highly-skilled human fraud fighters. I'll present attack trends and techniques we've seen through the past years and how the entire system has worked in cohesion allowing us to stay a step ahead of the bad actors.