Diseconomies of scale apply in wholesale finance too. Put a big order on a limit order book, and you'll exhaust the liquidity and move prices against yourself.

Diseconomies of scale apply in wholesale finance too. Put a big order on a limit order book, and you'll exhaust the liquidity and move prices against yourself. Dealers usually offer wider spreads for large trades as they'll have to work off a large position afterwards, and they need compensating for taking the risk of being on the wrong side of a major price move while they have the position.