There are many trading styles. I just have found that throughout my trading career that the safest trades are when stock remains above the 10 day moving average if you are a swingtrader or stays within an upward channel if you are longer term holder "INVESTOR".
First I agree that double bottoms are one indicator that may show a reversal in a stock, however there needs to be other supporting evidence to make the entry.
Improving MACD, OBV, STOCHS, RSI, to name a few... In addition, resistance, pivot, backtesting, Moving Averages, Trendlines, and support levels need to be evaluated.
On many double bottom "boxes" that occur below the 10 day moving average your will find the 10 day moving average then becomes a resistance level.
ZBRA Currently: MACD - Downtrend STOCH - Downtrend OBV - Downtrend RSI - Downtrend Volume 1/2 of daily average on Friday Channel break to the downside Trading below 10 day moving average
The one thing ZBRA has going for it currently is the fact it is sitting on a heavy support level at 78.46. On Friday this support was tested at the 78.50 area. If this stock comes back down and repeatedly hits this support level and the indicators continue their downtrend IMHO this support will break and hit the support levels outlined on the below referenced chart.
MACD in downtrend STOCH in downtrend OBV in slight uptrend (looks good) RSI neutral Lots of support from 22.89 up.
Monday is very important for this stock.
Looking at the chart on June 23, & June 24 is a prime example of a boxed (double bottom) that bounced nicely. There was plenty of supporting technical indicators to support this bounce.