Abstract: |
Building on observations by Sch\"oneborn (2008), we consider a Nash
equilibrium between two high-frequency traders in a simple market impact model
with transient price impact and additional quadratic transaction costs. We
show that for small transaction costs the high-frequency traders engage in a
"hot-potato game", in which the same asset position is sold back and forth. We
then identify a critical value for the size of the transaction costs above
which all oscillations disappear and strategies become buy-only or sell-only.
Numerical simulations show that for both traders the expected costs can be
lower with transaction costs than without. Moreover, the costs can increase
with the trading frequency when there are no transaction costs, but decrease
with the trading frequency when transaction costs are sufficiently high. We
argue that these effects occur due to the need of protection against predatory
trading in the regime of low transaction costs. |