This slides presents two types of simulation in trading system: trade shuffling and trade simulating. Trade shuffling is common in most trading system software using trades from a backtest and randomly shuffling orders of those trades to get many equity curves and also CAR and MDD. On the other hand, trade simulating requires application to run many backtests to get a set of results, equity curves. Its simulation and random takes place in modeling slippage, missing trades, noise, and many others in order to get results that close to actual trading operation. In the end, comparisons between trade shuffling and trade simulating are discussed along with their advantages and disadvantages.