Shares of Apple (AAPL) had their worst day in nearly four years today as the stock dropped more than six percent and lost around $40 billion in market cap. The last time AAPL had a larger one-day decline was on 12/17/08. It has surely been … The post Apple stock's worst day in nearly 4 years appeared first on Smarter Investing . Covestor Ltd. is a registered investment advisor. Covestor licenses investment strategies from its Model Managers to establish investment models. The commentary here is provided as general and impersonal information and should not be construed as recommendations or advice. Information from Model Managers and third-party sources deemed to be reliable but not guaranteed. Past performance is no guarantee of future results. Transaction histories for Covestor models available upon request. Additional important disclosures available at http://site.covestor.com/help/disclosures. For information about Covestor and its services, go to http://covestor.com or contact Covestor Client Services at (866) 825-3005, x703.