That's the story at retail broker TD Ameritrade (AMTD - Get Report) too. Like Garmin, TD Ameritrade is forming a double bottom pattern, with two swing lows finding support right around $15. For AMTD, the breakout comes on a move above $18.
There's some extra confirmation coming from momentum right now as well. 14-day RSI has been in an uptrend since Bottom 2 started forming, a sign that price was starting to increase at an increasing rate. Because momentum has been a good predictive indicator for the stock over the past year, that push to new highs in RSI is an auspicious sign for AMTD shareholders. Remember, an overbought reading isn't necessarily a bad thing -- statistically stocks that become overbought are likely to get more overbought in the near-term than they are to reverse.
Even though this stock has further to move higher before the breakout happens (GRMN, for instance, is just below its resistance level right now), the big benefit is that high correlations in the broad market will make similar setups like Garmin good predictors for what happens in AMTD. Don't buy this name until the breakout actually happens...