Diversification only insulates a portfolio from decline if assets remain uncorrelated. Stock market crashes are largely non-diversifiable within the stock market. This is because the correlations between stocks increase dramatically in volatile market conditions. Such is the fate of Direxion’s Daily Technology Bull fund, hereinafter referred to as TECL. The following companies comprise the top ten components of TECL, abstracted on 16 March 2020 and alphabetized by company name: Accenture (ACN) Adobe (ADBE) Apple (APPL) Cisco (CSCO) Intel (INTC) Mastercard (MA) Microsoft (MSFT) Nvidia (NVDA) Salesforce (CRM) Visa (V) Each company was added to the Security Explorer on our Ticksift platform.
The correlation coefficient, r, measures the strength of a linear relationship between variables, but not its significance. The null hypothesis of zero correlation between variables, r = 0, can be refuted by a statistical test where the associated p-value is a function both of the magnitude of correlation as well as the sample size. In general, larger sample sizes with larger |r| values are more significant. But how often do p-values and sample size simultaneously increase?