An overly concentrated market may be a bad thing for the S&P 500 (^GSPC) if earnings this week from Microsoft (MSFT), Amazon (AMZN), and Meta (META) reveal major increases in AI capital expenditures that show no signs of slowing anytime soon. Why it matters: The market didn't view Alphabet's second quarter capex numbers favorably when it reported last week. Alphabet's second quarter capital expenditures came in at $44.9 billion, slightly above Wall Street forecasts of $44.7 billion. The bottom line: It's reasonable to expect Microsoft, Meta, and Amazon to report eye-popping capex increases this week for the second quarter. Click here for in-depth analysis of the latest stock market news and events moving stock pricesRead the latest financial and business news from Yahoo Finance