Grantham on how to pick a bubble and bust

Jeremy Grantham is one of the world’s great investors. One of those rare birds that sees the system for the bubble machine that it is but can still play successfully within it.

In his latest quarterly newsletter, Grantham (and his deputy Edward Chancellor) devotes considerable energy to the question of what is a bubble, how to pick one and when such things burst. Here are his conclusions:

Best Guesses for the Next Two Years

With the repeated caveat that prudent investors should invest exclusively or nearly exclusively on a multi-year value forecast, my guesses are:

1) That this year should continue to be difficult with the February 1 to October 1 period being just as likely to be down as up, perhaps a little more so.

2) But after October 1, the market is likely to be strong, especially through April and by then or in the following 18 months up to the next election (or, horrible possibility, even longer) will have rallied past 2,250, perhaps by a decent margin.

3) And then around the election or soon after, the market bubble will burst, as bubbles always do, and will revert to its trend value, around half of its peak or worse, depending on what new ammunition the Fed can dig up.

Conclusion and Summary

The bull market may come to an end any time, indeed as I write it may already have happened. It could be derailed by disappointing global growth, profits sagging as deficits are cut, a Russian miscalculation, or, perhaps most dangerous and likely, an extreme Chinese slowdown. But I believe it probably (i.e., over 50%) will not end for at least a year or two and probably not before it reaches a level in excess of 2,250 on the S&P 500. Prudent long-term value investors will of course treat all of the above as attempted entertainment (although I believe all statistically accurate) and be prepared once again to prove their discipline and man-hoods (people-hoods) by taking it on the chin.

I am not saying that this time is different (attention Edward Chancellor). I am sure it will end badly. But given this regime of the Federal Reserve and given the levels of excess at other market peaks, I think it would be different to end this bull market just yet.

As you read the letter (and you absolutely must), remember that Grantham and his team see Australian property as a bubble and much of China as well, and recall that there have been no examples of such phenomena failing to revert to mean.