Carpetbagger
Originally this word dated back to the American Civil War and was the description given to Northern investors who went to the South after the war to profit from the reconstruction.
It suggests a certain lack of moral commitment to the enterprise involved - the investor only being after the biggest and fastest buck possible.
It came back into common usage in the mid-1990s. Millions of building society members rushed to open accounts to qualify for windfall handouts.
Predictably membership of those societies which had announced plans to de mutual ise soared.
So did membership of others as investors gambled on where the next windfall would come from.