A nervous few days for banks.

The Reserve Bank's expected to make its final decision this Thursday on whether to raise the amount of money it expects banks to hold in reserve.

Greg Smith from Fat Prophets expects it to go ahead with the proposal to almost double the capital requirement.

He told Kate Hawkesby that may take the wind out of the economy at precisely the wrong time.

"Particularly with those Aussie banks as well, they count for around 80 per cent of all banks lending, and there are talks they may pull back."