比特币泡沫会不会破裂 各路英雄纷上赌桌

To open an account, it has to be funded with 0.1 bitcoin, which will cost $110 as of Thursday morning.
开立账户必须提供0.1个比特币，按周四上午的价格约合110美元。

The put option costs 0.045 bitcoins, leaving 0.055 bitcoins still in the account.
看跌期权的成本为0.045个比特币，账户中剩余0.055个比特币。

After our imagined 55% plunge, the value of the put contract has soared to 0.12 bitcoins.
按照我们上面的假设，比特币价格暴跌55%之后，看跌合约的价值将上涨到0.12个比特币。加上账户中剩余的金额，目前共有0.175个比特币。

At a bitcoin price of $500, that's a mere $87.50.
而按500美元的单价将比特币兑换成美元，仅有87.50美元。

That means even if you are right, and you call the top of the bitcoin bubble, correctly predicting a whopping 55% plunge in the value of the currency and do all of this, you would lose $22.50.
这意味着，即便投资者的决策正确，预测了比特币泡沫的极限，也准确估算出比特币价格暴跌跌55%的事实，可最终依然要损失22.50美元。

You can get around this by upping your bet against bitcoins. If instead you buy two contracts, for $99, and once again the price plunges 60%, you will end up making a whopping $15. And I haven't factored in fees, which would probably run you about $4 for the whole transaction, including the dollar-to-bitcoin round trip, taking your profit down to $11.
投资者也可以通过加大做空投入来减少损失。如果投资者以99美元买入两笔合约，而比特币价格还是下跌60%，最终投资者可以获利15美元。这其中尚未考虑手续费，整笔交易的手续费约为4美元，包括美元与比特币的兑换费用，此时利润将降至11美元。

On top of all that, this isn't like trading on the New York Stock Exchange. Midday Wednesday, MPEx appeared to shut down, and the prices of the contracts disappeared. I was told this happens a lot. As of early Thursday, the exchange still wasn't listing prices. What's more, after running through my math of the trade with a Coinbr broker in a chat room, with the conclusion that there basically the trade doesn't make sense, he offered to sell me contracts at 0.033 bitcoins, so I could buy three contracts instead of two with my 0.1 bitcoins. That led me to question just how real the prices MPEx was quoting were.
此外，比特币期权交易并不像在纽交所（New York Stock Exchange）进行的交易那样。周三中午，MPEx关闭交易，合约的价格不知所踪。据称这种情况经常发生。截止周四早些时候，该交易所仍未公布价格。而且，我与Coinbr的经纪人在会议室计算了相关交易数据，最终我得出的结论是，这种交易毫无意义，于是他主动提出将合约按0.033个比特币的价格出售给我，这样一来，0.1个比特币便可以购买三份合约，而不是两份。这让我不由得质疑，MPEx所报的价格到底有几分可信。

All of this may explain one reason why the price of bitcoins until recently has been heading straight up. Why bother betting against it?
这或许也解释了为何近期比特币的价格会一路暴涨。既然如此，为什么还要费心去做空它呢？