I used to write on investing from a fundamentals perspective. I saw the housing crash coming in 2004. See my "http://www.downside.com/news.html", where I wrote:

"The next crash looks to be housing-related. Fannie Mae is in trouble. But not because of their accounting irregularities. The problem is more fundamental. They borrow short, lend long, and paper over the resulting interest rate risk with derivatives. In a credit crunch, the counterparties will be squeezed hard. The numbers are huge. And there's no public record of who those counterparties are.

Derivatives allow the creation of securities with a low probability of loss coupled with a very high but unlikely loss. When unlikely events are uncorrected, as with domestic fire insurance, this is a viable model. When unlikely events are correlated, as with interest rate risk, everything breaks at once. Remember "portfolio insurance"? Same problem.

Mortgage financing is so tied to public policy that predictions based on fundamentals are not possible. All we can do is to point out that huge stresses are accumulating in that sector. At some point, as interest rates increase, something will break in a big way. The result may look like the 1980s S&L debacle."

In 2006 I wrote:

"Interest-only loans as a percentage of new loans. (Graph) (Data from Loan performance)

People with these loans are not homeowners. They're renters, with an option to buy. One interest-rate spike and they're out on the street."

It took longer for this to crash than I expected. Mostly because the Fed pushed out cheap money to delay the crash. I was expecting an interest rate spike, but that didn't happen. I also didn't expect the thing to cascade so badly; I though the problem was going to be comparable to the 1980s S&L mess, not worse.

A key number to watch is the ratio of median house price to median income. Historically, that runs around 2.7. Above 3, trouble begins; people can't make their house payments. In the last bubble, it passed 4 for the US nationwide, and 10 for California. For that graph, see [1]. Click on "Price to Income". Look at the line for "United States". It's about 3.3 now; it hit about 4.1 before the last crash, then dropped to 3.0. Look at the graphs for California cities; they're much higher. But not as high as last time, yet. Keep watching those numbers; they're a leading indicator of a housing bubble/crash.

The problem with speculating on this is market timing. You can see the stresses building up, but it's hard to tell when the system will break. Those way-out-of-the-money option strategies hit this - you lose money every year as you wait for the big event. Burry almost ran out of time and money that way. Taleb, the "black swan" guy, doesn't release the results for his Empirica hedge fund for years other than the one year he hit the jackpot. His people got really upset when someone leaked them, they made it into Wikipedia, and he didn't look so good.

(On other fronts, I expected peak oil to be a bigger problem than it was; fracking fixed that, for now. And I thought Bitcoin would collapse long ago; instead, its use case for getting money out of China made it valuable.)

[1] http://www.economist.com/blogs/graphicdetail/2015/11/daily-c...