By Kriti Gupta, Bloomberg reporter and macro commentator

Stock investors worried about inflation should pay close attention to the rising price of oil. It could be the final kick needed to derail the consumer-spending spree behind the U.S.'s surging growth. From groceries to housing materials to gasoline, life is getting expensive for the average American, even those lucky enough to hold on to their jobs through the pandemic.

Take food. In the last six months alone, the Bloomberg Agriculture Subindex has risen 20% -- a margin not seen since 2010-2012. That was when the world's supplies were roiled by a series of global weather events, including a severe U.S. drought and a massive Russian fire that destroyed some of the nation's grain crop. Countries where bread is a staple, like Egypt and Tunisia, were hit badly. Geopolitical analysts say it helped set off the Arab Spring.