We report evidence that the presence of hidden liquidity is associated with greater liquidity in the order books, greater trading volume, and smaller price impact. Limit and market order submission behavior changes when hidden liquidity is present consistent with at least some traders being able...

The paradox of monetary profits has been a recurrent theme in macroeconomics since the problem was first formulated by Marx. Capitalists as a whole can at most get from workers, what they already paid out in wages. Marx did not solve this problem, and neither did Keynes, who had to face the...