What it is
Volume dry-up is the quiet stretch before a move. A stock that has been trending pulls back or goes sideways on well below normal volume. The sellers who wanted out are already out, and nobody is pushing it lower. Few shares are on offer, so it does not take much buying to move the price.
How Breakaway uses it
VDU fires when RVOL is 0.7 times the 20-day average or lower. RVOL, or relative volume, compares today's shares traded with that 20-day average. VDU is the opposite of the VOL trait, and only one of the two can be lit on a given day. VDU means the most when the trend traits are still lit. That is the picture of a healthy stock resting.
How to read it
Look for VDU together with a compression trait such as NR7 or the Bollinger squeeze. A tight, quiet range inside an uptrend comes before many of the best breakouts. That is why those traits are grouped as predictive on the card. The move to watch for is the first day that flips VDU to VOL with a close near the high.