The value of Bitcoin keeps sliding by Miguel Helft @FortuneMagazine September 19, 2014, 1:39 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Call it the summer of the incredibly shrinking Bitcoin. While many venture capitalists remain enthusiastic about the crypto-currency, this has not been a good season for Bitcoin. Since reaching a July high of nearly $650, the price of Bitcoin has been on a steady decline. On Friday, it dropped below $400. Why? No one really knows. Overall, Bitcoin has been far less volatile than in the past, which Bitcoin fans will tell you, is a good thing. Currencies, if they are going to be useful, should have a somewhat predictable value. Bitcoin’s recent decline hasn’t been sudden. But it has been steady. Prior episodes of Bitcoin volatility were typically precipitated by some event, like the meltdown of Bitcoin exchange Mt. Gox early this year or the actions or statements of a regulator in a major market like China or the European Union. This summer, there were no blockbuster Bitcoin news, good or bad. I asked a couple of Bitcoin boosters to theorize about what was happening to the currency. Deafening silence. Maybe it’s that those who bought Bitcoin hoping for a quick gain got tired of waiting for their payday. The decline of the last few days may be due to the fact that the Scots, after all, won’t be needing a new currency or that speculators are now putting their money in Alibaba. Those are just hypotheses worthy of a tweet and not much more. It’s entirely possible that Bitcoin will recover. It could also fall further. But it seems pretty certain that predictions of a $50,000 Bitcoin will have to wait. Disclosure: I own a small amount of Bitcoin, which I bought to understand how digital wallets work. I paid more than the current price.