[dgcupps]

One thing to keep in mind is that people who are buying 30 year bonds often aren't planning on holding them to maturity; rather, they are looking for an asset that is relatively stable in value while also generating a small return.

Can you estimate the probability of your scenario? Sure, you could use the historical volatility of equity returns to calculate the chance of that happening. However, unless you add in other factors that you think could realistically hurt future equity returns, I think you'll find that probability to be very small.