Your calculation of cumulative probability is false because...

Your calculation of cumulative probability is false because events 1-5 is not independent, i.e. they have correlations. Therefore the actural probability figure after adding 20 items of covariance is much higher and in fact the final figure is dominanted by covariance instead!
Nevertheless I am not trying to use detailed probability calculation here as I could well be on track making a precise mistake, this is what I want to avoid. The general logic is simple economics, the rising interest rate in the US will come this year or next, and that would have a high chance of causing (I use this word because econmics can explain the correlation quite convincingly already, plus majority investors would act accordingly anyway) events 2-4. Price may not need to be lower to derail profit figure, a slow down in revenue account e.g. getting harder to sell new built houses in pre-determined time-frame can do the same job.