This price-volume factor suggests that a trend reversal may be coming - Bitcorn may be going up.
At the same time, notice that XRP has had a couple of waves up.
The most recent one has shown a price increase with volume decrease, which is also anti-trend, possibly suggesting a reversal.
You said;
Bitcoin > price and volume decrease = the price will rise
xrp > price increase but volume decrease = the price will fall
I don't know how it works about price and volume, never pay attention to the volume before.
XRP price increase in the early of the year such as in 2017 due to banks use xrp to move their funds, but it will come to the end after few months, maybe in April or May.
But bitcoin may fluctuate at the current range for a while such as in the last few weeks, bitcoin has some minor rises and decline, it will increase if scale development implemented or the acceptance of bitcoin increases.