https://i.imgur.com/Ubos4bs.jpg
On the 16th of april we had a lovely hammer candlestick formation which usually predicts a reversal. Strong volume indicated that the smart money successfully accumulated a huge position at the best price.
Drops tend to be sharper than rallies. That is why volume might work as an indicator. If we assume that the big investor is also the wiser investor, then your explanation could make sense.