Final answer:
The claim that all 10-year periods in the stock market history have been profitable is false due to the variability and risks associated with market performance, including years of modest or negative returns.
Step-by-step explanation:
The statement that '100% of the 10-year periods in the history of the stock market made money' is false. Although the stock market has provided a high rate of return over extended periods of time, there are no guarantees, and the historical performance shows variability. There are times when the stock market, as a whole or individual company values, can experience substantial declines over short or long periods. This includes times like the 1970s and the first decade of the 2000s where returns were modest or even negative, and sharp declines such as in 2008 during the financial crisis.