In this video from The Motley Fool's Ask a Fool series, analyst David Meier takes a question from a reader, who asks, "What's up with Facebook (META 0.72%)? It doubled but now it's dipping." After Facebook's volatile IPO and dramatic subsequent fall, many investors still have a hard time trusting this stock, even as it continues to strengthen and push beyond its IPO levels. David gives investors three reasons why he believes there's no reason to worry about your Facebook investment over the long term.