With little to no transparency, trader's ability to verify transactions becomes virtually impossible, at least if one does not have faith that the market exchange is operating in a well-run fashion, a problem that is unlikely with the major brokerage services open to institutional investors (e.g. Reuters, Bloomberg, and Telerate). In a situation with a problematic market exchange lacking transparency, there would be no trust between the client and the broker, yet surprisingly, there is nonetheless demand to trade in dark pools.