Not necesarily. Some people made HUGE amounts of money during WW2.
In a WW3 scenario, neither these people nor much else will be left standing. Can your lizard friends not tell you about the effects of a nuclear exchange between two super powers?
Even a limited regional exchange (50 tactical nukes each side) can have vast effects on the entire northern hemisphere and dent the weather/climate/food suppliers for a long time. Humanity won't die out but our way of life will change (and lots will die through malnutrition, radiation poisoning, etc.)
A global exchange will kill everyone and everything. The ultimate profit then becomes absolutely meaningless.