Hi,
I don't understand very well this idiom I have found.
I know the meaning is that by desperation they threw themselves out of the windows of Wall Street, but I don't see it so clear:
'My brother was born the year the stock market crashed and all the rich white men started JUMPING OUT OF THEM Wall Street windows'
A common grammatical error by some native speakers is to say 'them' instead of 'those', eg 'them cars' instead of 'those cars'.
Thus, the phrase is really '. . . the year . . . all the rich white men started jumping out of those Wall Street windows'.
It's not really an idiom here, because it describes what actually happened.
Best wishes, Clive