The least true statement about beta is "The average beta of all stocks in the market is zero." This statement is incorrect because the average beta of all stocks in the market is not zero. Beta measures the systematic risk of a stock or investment relative to the overall market. A beta of 1 means that the stock moves in line with the market, while a beta greater than 1 indicates the stock is more volatile than the market. On the other hand, a low positive beta (below 1) implies low systematic risk. It means that the stock's returns will move in the same direction as the market's returns, but with a smaller magnitude. For example, if the market has a beta of 1, and a stock has a beta of 0.8, it suggests that the stock is less risky than the overall market. This means that if the market goes up by 10%, we can expect the stock's returns to go up, but by a smaller amount, say 8%. Similarly, if the market declines by 10%, the stock's returns may decline, but by a smaller amount, such as 8%. In summary, a low positive beta indicates low systematic risk, and the stock's returns move in the same direction as the market, but with a smaller magnitude. So, the correct statement is that a low positive beta (below 1) means low systematic risk.