"The investor who permits himself to be stampeded or unduly worried by unjustified market declines in his holdings is perversely transforming his basic advantage into a basic disadvantage." -- Benjamin Graham.Whether the declines are "unjustified" or not is likely up for debate. But what's not debatable is that shares of connected-TV platform company Roku (ROKU 2.75%) and energy drink maker Celsius Holdings (CELH -3.33%) are down by large amounts. As of this writing, Roku stock is down 84% from its all-time ...