Arpit Gupta, a Ph.D. student in finance at Columbia University’s Graduate School of Business, contributed to this column.

Just as the recession in the early 2000s became linked with the bursting of the tech bubble, for many the financial crisis in 2008 has been synonymous with the blow-up of subprime mortgages.

But there was more to 2008 than that.

Gary Gorton, an economist at Yale, recently published an analysis that shows how well some subprime mortgage-backed securities have performed over the past few years – a very counterintuitive conclusion. Citing one of his graduate students, Gorton explains that AAA/Aaa-rated subprime bonds issued in the peak bubble years (when mortgage underwriting was arguably the weakest in history) were only down 0.17 percent as of 2011. In other words, the highly rated subprime bonds – or toxic assets so associated with the financial crisis – have experienced only minimal losses since the bubble popped.

Of course, that bond statistic ignores the numerous costs borne by the federal government in response to the crisis. For example, the mortgage giants Fannie Mae and Freddie Mac required more than a $150 billion bailout, and the Federal Reserve dropped and held interest rates to historical lows, in part so that millions of homeowners could refinance their mortgages (often into new mortgage products that were also backed by taxpayers through another government program). That is, it’s important to acknowledge that subprime mortgage products have done relatively well partly because of post-crisis government interventions that were costly for taxpayers.

Nevertheless, the subprime bonds’ better-than-expected performance can help us think through the broader role of highly rated securities in the financial crisis. In particular, it helps focus our attention away from the assets themselves (as it now appears that some subprime securities held up surprisingly well) and toward how the assets were financed using leverage and risky holding structures.