Just like investments in Bitcoin startups are binary, so are investments in Bitcoin itself. Put some USD into it and don't worry too much about it. People waste millions on lottery tickets with much smaller chances of success, so, I'm tired of all these negative articles, just because Bitcoin dropped 20-30% and then almost fully recovered in a day. Sell off if you wish - there are enough people to buy your Bitcoins cheap. And by the way, the tulip craze is an obvious myth.