Buying the dip may not make sense.Shares of cloud identity-management company Okta (OKTA -0.73%) have provided investors with disastrous returns over the last three years that were made worse by a huge sell-off in the stock following the tech company's fiscal second-quarter earnings report. Shares are down more than 20% since the Aug. 28 report.Though it might be tempting to buy the dip in this growth stock, investors may want to think twice before they do. This may be a growing company, but that doesn't me ...