 It is standardly assumed, as in the version of the DBA given in section 1.2, that an agent will be willing to buy or sell a bet on \(S\) for which her credence matches the betting quotient.  But in practice, buying a bet may have a different value for an agent than selling that bet, because there is typically a lag between the time that a bet is placed and when it is settled, as Rowbottom (2007) points out.  Selling a bet involves collecting a sum up front and potentially paying out latter, which often has greater value than paying the same price up front and with the potential payoff obtained later.  This asymmetry between the value of buying and selling bets also constrains the situations in which a Dutch Book can be made.