In order to analyse and/or predict the trend in transactional price in the pair of BTC-USD I definetely need historical data. I don’t know yet what granularity is needed not mentioning time period needed to perform data mining.
Majority of google results were limited to last 2000 entries for free, where rest was paid. Data resolution wasn’t ideal too – 1 entry per day. I believe I need real-time data.
I gave it a try to SpreadStreet.io, where registration takes a second after which I was able to download my very first data set for Bitcoin historical data from GDax exchange. CSV files looks like that: