Thanks Zebedee, at end of the day crypto's own strengths and weakness are the primary driver (ETHUSD is up 3000% + since Dec, EURUSD is only up 10%), but movements in quote currencies definitely have an effect ... very hard to quantify the magnitude though.
Re: ETH ICO's I think that was definitely a big driver behind the rally, likely the primary driver. Just like recent weakness is almost certainly a product of the high profile ICO fails.
I haven't checked out XRP, will have to take a look.