A "trading desk" refers to a dedicated area where people buy and sell financial assets, like stocks, bonds, or currencies. It is usually found in banks, brokerage firms, or investment companies. Full definition
What I suspect is more likely is that many people making this claim are just repeating what they have heard on trading desks since, well, forever. (ritholtz.com)
We have no proprietary trading desk to slow you down. (cobratrading.com)
Small investors and traders need to face the fact that unless they're paying a premium price, their access to market prices is several long minutes behind what institutional trading desks see. (automaticfinances.com)