As a principal architect, design a comprehensive microservices architecture for a global financial trading platform processing millions of transactions per second across multiple continents. The system must maintain ACID properties while achieving 99.999% availability, sub-millisecond latency for critical operations, and complete regulatory compliance across different jurisdictions. Your design should address: 1) Service decomposition strategy with clear bounded contexts; 2) Data consistency patterns that balance consistency and availability needs; 3) Circuit breaker and retry patterns for fault tolerance; 4) Event-driven communication mechanisms for eventual consistency where appropriate; 5) Multi-region deployment strategy with disaster recovery; 6) Security architecture including authentication, authorization, and encryption; 7) Observability stack with comprehensive monitoring and alerting; 8) Traffic management and rate limiting approaches; 9) Database selection and data partitioning strategy; 10) API versioning and backward compatibility approach. Include architecture diagrams, technology choices with justifications, and migration strategy from a monolithic legacy system. Discuss potential failure modes and their mitigation strategies.