High tight flag chart pattern forms when a stock rises over 90% (preferably 100%) or more in two months, then consolidates sideways for 15-25 days with a decline of no more than 25%. When there's a breakout of the sideways 'flag' on high volume, the powerful uptrend often resumes.
The entry point is either as the stock breaks the high of the flag or breaks a downtrend line - but only ever on higher than average volume.
Looking here for a breakout above either of the dotted lines on a day with high volume for a gain of between 20% to 100%, market conditions being favourable.