In effect, he was simply saying that the best time to be in any market is usually when most others are out.
In relation to the stockmarket, the time to be in is not, as an American epithet attests, when hotel bellboys are talking about shares. Money can far more easily be made when they go back to talking about baseball.
And, as Mr Rastani suggested, the 1930s Depression was not a disaster for everybody. For some, it presented that very opportunity.
A version of this leads people to seize the chance to take advantage of sale items offered by struggling retailers during a recession.
Yet when turmoil hits financial markets, people tend to become herd-like in their flight.
Perhaps this is because most have only a slight knowledge of such matters. All the more reason, therefore, to heed the frequent calls for more attention to be paid to cultivating a wider financial literacy.
The furore about the tenor, if not the tone, of Mr Rastani's remarks merely reinforced this.