E-mail: yoshihiko.sugihara@boj.or.jp / /2011.4 29 1. market impact transaction cost 1 1990 algorithmic trading alternative trading venues; off-exchange venues 1990 2000 1 2010 high frequency trading: HFT statistical arbitrage 2000 exchanges; 2010 2007 2010 30 /2011.4 Johnson [2010] optimal execution strategy 2011 2011 2009a, b 2 3 4 5 6 7 31 2. 1 Kissell [2006] fees commission delay costs taxes ti