Traders are also doing 7% of their volume in "dark pools, " the electronic equivalent of a back alley where buyers and sellers transact anonymously, according to Tabb Group, a Westborough, Mass. market researcher.
Down a narrow alley not far from the sparkling city centrepiece of Federation Square is dark, pokey Rutledge Lane, where a wild riot of colour spills over every surface and stretches storeys high.