Short-term volatility drives stock prices upward, research finds
While savvy investors might say that a stocks value is the determining factor for how much theyre willing to pay, Pitt researchers have shown that recent price trends and other aspects unrelated to a stocks value are important in determining the price investors actually pay.
A basic rationale for price movement is due to changes in the value of the asset. In the absence of any insight into the motivations of investors and traders, one might stipulate that prices should fluctuate randomly about this basic valuation, says Gunduz Caginalp, professor of mathematics at Pitt, one of the authors of the study.
But Caginalp and one of his students, coauthor Mark DeSantis, found strong statistical evidence that a short-term price trend tends to increase trading prices in financial markets, to a magnitude of almost half that of valuation.
The researchers also found statistically significant positive impacts on the price with respect to the stocks short-term volatility and volume trend, as well as to the nations money supply. According to the study, the findings about the money supplys impact validate asset-flow theory, which holds that additional cash fuels trading price increases.
Caginalp finds the positive correlation of stocks short-term volatility to price surprising.
In classical finance, the inverse risk-reward relationship stipulates that high volatility should be interpreted as greater risk, which should diminish the price that traders would pay for the stock, he said.
Caginalp hypothesizes that traders are attracted to high volatility because they foresee volatility as an opportunity for greater profits.
In conducting the study, Caginalp and DeSantis had direct contact with data: The researchers analyzed a data set consisting of 111,356 records from 119 funds, corresponding with the daily closing prices of those funds for the 10-year period from Oct. 26, 1998, through Jan. 30, 2008.
Papers that discuss motivations beyond valuation rarely have direct contact with market data, says Caginalp. As such, it is easy for exponents of efficient market theories to dismiss them.