Buying or selling ETF shares on an change may require the payment of brokerage commissions. The optimized bodily replication method is especially appropriate for very broad-based indices. For instance, the MSCI World Index includes approximately 1,600 stocks from a wide selection of markets, jurisdictions and currency zones. Accordingly, full physical replication of the index would contain high transaction costs. A variety of these securities usually are not very liquid or have solely minimal impact on the efficiency of the Index due to their low weighting.