ARTICLE SYNOPSIS ...Position Trading The S&P by Clifton Mitchell, Ph.D. Use linear regression to predict short-term trend changes of the Standard & Poor's 500. Psychologically speaking, bar chart lows represent the lowest price that sellers are willing to take for a security or commodity. If sellers are not willing to go lower on their selling price, then buyers must pay more and, consequently, prices rise. This is why a series of higher lows has long been accepted as a general indicator of prices moving higher. Evidence of this is most commonly seen when trendlines indicating upward movement are drawn such tha...