The bid-ask spread is the difference between the price a market maker is willing to buy an asset and the price it is willing to sell at (Commission Staff Working Document Impact Assessment Accompanying the document Commission Delegated Regulation supplementing Regulation (EU) No 600/2014 of the European Parliament and of the Council with regard to definitions, transparency, portfolio compression and supervisory measures on product intervention and positions {C(2016) 2860 final} {SWD(2016) 156 final}, 18.5.2016, SWD(2016) 157 final, p. 59).