Checking for a condition over a period of time

Is it possible to check if one condition is satisfied for multiple candles? Ex. if buy volume for current candle greater than buy volume for previous candle for the past 4 candles then send alert? Is it possible with Pi if it’s not possible with Sentinel?

Sentinel alerts aren’t based on technicals or candles. You can check out http://streak.tech/ see if it suits your requirement