As history has proven, many investors are more fearful during market pullbacks, selling when they should be buying. But for more opportunistic investors willing to hold stocks through thick and thin, this sell-off is causing some good buying opportunities to surface. High growth companies like Square, Salesforce, and Amazon.com, for instance, have dropped 24%, 14%, and 13%, respectively, during this period. But one timely opportunity surfacing amid October’s sell-off looks especially attractive…