Inputs are the number of bars to check correlation for (default 10) and the the ticker to use for BTC comparison (default is BITFINEX:BTCUSD)
Values of 1 are highly correlated (i.e. bitcoin moves up, so does your current ticker), values of -1 are inversely correlated (i.e. bitcoin moves up, your current ticker moves down).
See: https://www.babypips.com/learn/forex/wha... for some more details on correlation