Are There Commission Cost Side-Effects from Portfolio Management Decisions?

An examination of approximately 28,000 institutional trades over five post-Mayday quarters indicates that security price and liquidity are important determinants of commissions. High priced stocks, being more liquid, are generally less costly to trade than low priced stocks. Possible inventory risks, as measured by the standard deviation of returns, are positively related to commissions, but the explanatory power of this variable is not as great as that of liquidity or price and its practical importance is minimal