[C]apitalist savings 'lead' profits. This result may appear paradoxical. 'Common sense' would suggest the opposite sequence—namely, that savings are … - Michał Kalecki

It is indeed paradoxical that, while the apologists of capitalism usually consider the 'price mechanism' to be the great advantage of the capitalist system, price flexibility proves to be a characteristic feature of the socialist economy.

It is the export surplus and the budget deficit which enable the capitalists to make profits over and above their own purchases of goods and services.
The connection between 'external' profits and imperialism is obvious.

It has been frequently assumed that V is constant; and this indeed is the cornerstone of the quantity theory of money. But it seems fairly obvious that the velocity of circulation in fact depends on the short-term rate of interest.