At the start of this week, the question was whether the shock of China’s supercheap AI DeepSeek would compel Silicon Valley’s big artificial-intelligence companies to reduce their spending. Now, we can say the definitive answer is no.

Amazon.com Inc., Alphabet Inc., Meta Platforms Inc. and Microsoft Corp., the country’s leading hyperscalers, are embarking on an unprecedented year of spending — a combined $325 billion in projected capital expenditures for 2025.