[steeleduncan]

The success of bitcoin (amongst other cryptocurrencies) has led to great investor interest in blockchain techologies. Investments in these technologies are generally made by way of an ICO, usually denominated in bitcoin and/or ether. This increases demand for bitcoin & ether which raises the price and generates even more investor interest in blockchains/cryptocurrencies, leading to further ICO's and so on.

There are of course speculators, and an increase in the number of businesses accepting bitcoin for regular transactions, but I suspect the ICO boom is likely the driver behind the recent spike.

It is the same mechanism noted by Paul Graham in his time at yahoo - http://www.paulgraham.com/yahoo.html