GMO called the US housing bubble perfectly, warning loudly on the way up.

True: GMO publications (e.g., Grantham's quarterly letters) dated before the 2006–2007 US housing peak explicitly warn that US house prices are in a bubble, and those warnings were prominent and repeated ('loudly'). Mostly true: clear pre-peak warnings exist, but they came late in the run-up or were not repeated much, or some details of the call (e.g., the timing of the decline) were off. Mixed: warnings existed but were hedged or occasional, or covered only part of the picture. Mostly false: GMO raised housing concerns only in passing, or only near or after the peak. False: GMO's dated pre-2007 publications show no housing-bubble warning, or show it dismissing the idea of a bubble. GMO's own retrospective statements alone do not settle it; the dated pre-peak documents do.

Set before the research began.

1. E1 If it's a bubble, it's still built on a boom Los Angeles Times · 27 May 2007

   ““From Indian antiquities to modern Chinese art; from land in Panama to Mayfair; from forestry, infrastructure and the junkiest bonds to mundane blue chips; it’s bubble time!” wrote Jeremy Grantham, head of Boston money manager GMO, in a letter to clients last month.”

2. E2 GMO’s Mean-Reversion Strategy Is Tested in Today’s Market Institutional Investor · 25 July 2016

   “In 2006 and 2007, as GMO managers got more defensive and housing hit new highs, the firm’s performance slid, but Grantham knew what was ahead and said as much in his quarterly letters.”

3. E3 This fund tracks 36 bubbles—and 33 have completely popped Quartz · 8 May 2025

   “Grantham accurately predicted the housing bubble—which went along with a bubble in profit margins for corporations—in 2005 (pdf).”

4. E4 Investment Capabilities GMO Own record

   “Jeremy Grantham's 1Q 2007 letter to clients discusses the necessary conditions for a market bubble, and why it's difficult to pinpoint when the bubble will burst or the particular catalyst for the burst.”

Independent secondary accounts say Grantham warned of the housing bubble in 2005 and in his 2006–2007 letters [E2][E3], but no dated pre-peak GMO document text on US housing is in the evidence, and the 2007 letter excerpt does not name US housing [E1][E4]. The material therefore does not show how prominent, repeated or well-timed the warnings were, which the criteria require to settle the claim.