Round numbers, clustering and reflective barriers in the stock market

Abstract

In an attempt to analyze the random walk hypothesis as the process governing the behaviour of financial asset prices, we study the presence of clustering as well as support and resistance barriers in price series through a number of statistical tests on a sample of 100 companies belonging to the S&P 500. According to our results, there seems to be a significant level of clustering at round numbered price levels, a conclusion aligned with previous literature. However, further tests indicate we cannot assert the existence of barriers.