Dr. Vladimira Ilieva and Mark DeSantis* focused on large scale data studies that effectively subtracted out the changes due to the net asset value of closed end funds [15]. Thus one could establish significant coefficients for price trend. The work with DeSantis was particularly noteworthy in two respects: (a) by standardizing the data, it became possible to compare the impact of price trend versus changes in money supply, for example; (b) the impact of the price trend was shown to be nonlinear, so that a small uptrend has a positive impact on prices (demonstrating underreaction), while a large uptrend has a negative influence. The measure of large or small is based upon the frequency of occurrence (measure in standard deviations). Using exchange traded funds (ETFs), they also showed (together with Akin Sayrak) that the concept of resistance—whereby a stock has retreats as it nears a yearly high—has strong statistical support [16].
