This chapter shows the cases that AMAFMMs investigated new financial exchanges for high-speed era. The first one discussed how much of an increase in speed is needed for market efficiency, and showed that latency should be sufficiently smaller than the average order interval for a market to be efficient. The second one analyzed the profits/losses and risks of market maker strategies (MM) and investigated whether MM can continue to provide liquidity even on a frequent batch auction (FBA) that is a kind of slow exchange, and showed that MM cannot avoid a price variation risk intraday in the FBA. The third one investigated maker-taker fees and showed that the transaction costs of takers in the maker-taker fee market were not lower than those in the non-maker-taker fee market. The last one investigated how a dark pool affects financial markets’ efficiency and price-discovery function, and showed that there is an optimal usage rate of the dark pool for the market efficiency.