Today is all about AI capex.This is the range to watch: $435–475 billion.That's estimate capex for this year alone from Microsoft, Meta and Google, who all report after the bell. It's an astounding number that I want to put into perspective.because even people in markets have no idea how big the AI capex boom is.It's larger than the combined annual military spending of China and Russia.That's more than the entire government of Canada budget this year and approaches Germany's government budget.It's double the entire four-year Marshall Plan (inflation adjusted).It's nearly equivalent to the 35-year build out of the interstate highway system (inflation adjusted)It's slightly larger than entire global upstream oil capex budget.It's larger than the combined annual military spending of China and Russia.It's double than global pharma R&D spending.It's 3.5x global mining industry capex.Today we got a taste of the spending in the durable goods orders report:That doesn't even include Amazon, OpenAI and the others also spending massively on AI capex.Details and what's expected today:Alphabet — Watch for any revision to the $175–$185B 2026 capex range — that's nearly double the $91.4B spent in 2025 (those numbers are breathtaking). Options pricing about a 5.6% move in the stock on earnings.Microsoft — Microsoft doesn't guide on capex for the year but capex is estimated at $35.2B for the quarter and look for indications about about it "growing" or "stabilizing" or anything along those lines. Management said H2 spend would be larger than H1. Indications on multi-year spending will be notable as well.Meta — The guide on 2026 capex is $115–135B, up from $69.7B in 2025, with total expenses guided to $162–169B. This article was written by Adam Button at investinglive.com.