The surge of optimism among US investors pushed Wells Fargo/Gallup US Investor and Retirement Optimism Index to record high since September 2000 in the same month in 2017, and the Index remained strong in the fourth quarter. This upbeat reflects investors’ confidence in the economy outlook, stock market, unemployment and personal finances. The slump of business investment in 2015-16 leaves room for further improvement. Enhancement of the stock market will give corporates better access to stock markets to finance their growth.