Skip to navigationSkip to main contentSkip to right columnADVERTISEMENTJing PanMon, June 29, 2026 at 8:30 PM GMT+2 9 min readThe Diary of a CEO/ YouTubeMoneywise and Yahoo Finance LLC may earn commission or revenue through links in the content below.Market legend Jeremy Grantham has a history of calling out bubbles.As the co-founder of asset management firm GMO, he famously warned about the 2000 dot-com bust and the 2008 financial crisis. Now, he believes another major market reckoning is in the works.Dave Ramsey warns nearly 50% of Americans are making 1 big Social Security mistake —