South Korea's Kospi posted its biggest single-day gain ever after Microsoft earnings calmed AI-bubble panic. DeepSeek launched the public beta API for its V4-Flash model on July 31, the same week OpenAI cut GPT-5.6 prices and Anthropic faces mounting cost pressure. At $0.14 per million input tokens with a 1M context window, V4-Flash undercuts OpenAI's newly discounted Luna tier by 30% and Haiku 4.5 by a factor of seven, intensifying an already live three-way price war for AI developer spend. DeepSeek's V4-Flash is not a new July 31 launch, but its price still lands hard after OpenAI's July 30 cuts. DeepSeek's own API changelog lists V4-Pro and V4-Flash as available from April 24, 2026, and the Hugging Face model card gives the same release date. DeepSeek's old deepseek-chat and deepseek-reasoner aliases were set to retire on July 24, while OpenAI has just cut GPT-5.6 prices. The official DeepSeek pricing page lists a one-million-token context window, a maximum output length of 384K tokens, OpenAI-format access at api.deepseek.com, and support for tool calls, JSON output and beta prefix completion. The model card lists 284 billion total parameters with 13 billion active per token through its