Most investors shouldn't wait for a perfect price when trying to build a position in a favorite stock, Fool contributor Tim Beyers says in the following video.

Rather, the best strategy is to dollar-cost average. Yet Tim says there are occasions when it's OK to make a huge bet. For example, when the stock of an otherwise high-quality business takes an unfair beating. Or when the market has failed to properly value a company that's positioned to cash in on a huge opportunity.

Tim says he's looking at Twitter (NYSE:TWTR) with just this sort of lens. The microblogger recently began offering marketers methods to target Promoted Tweets down to just a handful of individuals. Deals with Comcast and Nielsen to increase the usefulness of Twitter data should help to win their business. Mix in our rising dependence on smart mobile devices for social engagement -- more than half of U.S. mobile users now have a smartphone -- and you've the ingredients for continued outperformance, Tim says.

Do you agree? Are you making any big bets right now? On which stocks? Please watch the video to get Tim's full take, and then leave a comment to let us know where you stand.