The First Trust Total US Market AlphaDEX® ETF is an exchange-traded index fund. The objective of the Fund is to seek investment results that correspond generally to the price and yield (before the Fund's fees and expenses) of an equity index called the NASDAQ AlphaDEX® Total US Market Index. There can be no assurance that the Fund's investment objectives will be achieved. The NASDAQ AlphaDEX® Total US Market Index is an "enhanced" index created and administered by The NASDAQ OMX Group, Inc. ("NASDAQ") which employs the AlphaDEX® stock selection methodology to select stocks from the NASDAQ US Large Cap Index, the NASDAQ US Mid Cap Index and the NASDAQ US Small Cap Index that meet certain criteria. NASDAQ constructs the NASDAQ AlphaDEX® Total US Market Index by ranking the eligible stocks from the NASDAQ US Large Cap Index, the NASDAQ US Mid Cap Index and the NASDAQ US Small Cap Index on growth factors including 3-, 6- and 12- month price appreciation, sales to price and one year sales growth, and separately on value factors including book value to price, cash flow to price and return on assets. All stocks are ranked within each size class (Large, Mid, or Small) on the sum of ranks for the growth factors and, separately, all stocks are ranked on the sum of ranks for the value factors. A stock must have data for all growth and/or value factors to receive a rank for that style. NASDAQ classifies each stock as either a value stock or a growth stock and each stock receives its style rank from the previous step as its selection score. The top 200 stocks from the NASDAQ US Large Cap Index, the top 400 stocks from the NASDAQ US Mid Cap Index and the top 600 stocks from the NASDAQ US Small Cap Index based on the selection score determined in the previous step comprise the "selected stocks". The selected stocks are divided into quintiles based on their rankings and the top ranked quintiles receive a higher weight within the index. Within each sub portfolio (Large, Mid, and Small), stocks are equally weighted within each quintile. The index is reconstituted and rebalanced quarterly.