While everyone watched GPT-5.5 launch, DeepSeek quietly shipped V4 the next morning. V4-Pro: 1.6T total / 49B active, MIT license.
V4-Flash: 284B total / 13B active.
Both with native 1M-token context. At 1M tokens, V4-Pro runs at 27% of V3.2's FLOPs and 10% of the KV cache.