Didin't you hear? China jailed the CEO of Bitcoin, an banned the sale of alcohol to miners.

Thanks!  But this is bad news anyway, isn't it? What do they mean by "cash withdrawal"?

Note that the price MAY recover temporarily after the panic, if and when the exchanges post notices on their websites explaining what has stopped and what will keep working until May 10th.

(Or may not...)

The new PBoC "clarification of the clarification" mentions cash too.  But I cannot figure out exactly what they mean.

There is a May 10th deadline:

Well, the 1d charts give another perspective... 

There is a guy monitoring them here.

EDIT: they now have 104'000 BTC, buying is erratic. Was 60'000 in November, 80'000 in February.

Hm, this looks serious. The Alipay news may have been just one of the consequences of that new "clarification" by the PBoC (and other agencies).

When the price drops in China, arbitrage traders immediately buy cheap coins there, move them to Bitstamp/BTC-e/Bitfinex/etc, and sell them for the still higher price.  That slows down the Chinese drop and pulls the price down in the west, until the prices about match (within some currency exchange rate, seems to be 6.30 CNY/USD these days).

Alipay MAY have been one of the ways that clients used to recharge Huobi's "recharge cards".

Found this on the Chinese language thread:
Could this be the cause of the dump? Does not seem particularly earth-shaking...

Thanks for the answers!

谢谢大家的答案！

No. I try to predict the price.  I am happy when I predict correctly. I don't care if it went up or down.

[ G. T. ] 不，我试图预测价格。我很高兴，当我预测正确。我不在乎，如果它上升或下跌。

[ Sorry for posting in English but I do not speak Chinese and do not trust Google Translate. ]

Is there a "standard" day of the month when salaries are paid in China?  End of every month? Beginning of every month?  Middle of every month?

The reason for asking is: perhaps more money enters the exchanges on certain days of the month than in others.  That would cause the price of BTC to go up.

[ Google translation follows.  I hope that it makes sense. ]
[谷歌翻译如下。我希望这是有道理的。]

有一个月的工资时支付在中国的一个“标准”的一天？每月结束了吗？开始每月？每个月的中间？

究其原因，问的是：也许更多的资金进入交易所在每月的某几天比其他国家小。这将导致BTC的价格上去。

I don't understand your notation, here is mine

Basically, in the log-Brownian model the difference between successive values of Z(i) = log(P(i)) are independent random variables with probability distributions that are symmetric about zero.  Therefore after any number n of steps the probability distribution of Z(i+n) will be symmstric about the starting value Z(i).  That means Z(i+n) wil be less than Z(i) with 50% probability.  Since log is monotonic, it preserves cumulative probabilities, therefore P(i+n) will be less than P(i) with 50% probability.  What is wrong with this argument?  

(Strictly speaking, "Brownian" requires a normal distribution of increments with zero mean and fixed variance.  In practice the variance varies slowly and the distributions have fatter tails than the norma; but by the law of large numbers they become near-normal for large n.)

Er, if it is a joke, I didn get it.  They will be held in Japan, by some Japanese auction house, I imagine.  With remote bidding, perhaps?

IF they decide to sell the coins, I expect that they will divide them into manageable lots, and auction them through some auctioning house.  I believe that would be the easiest way to get the best possible price for them. (The FBI will probably do the same with the SilkRoad coins, except that they will surely use the government auctioning services.) 

But that just pushes the question forward: what wiill the auction winners do with those coins?

Chinese Slumber Method prediction for Friday April 25

Prediction valid for: Friday 2014-04-25, 19:00--19:59 UTC (not before, not after)
Huobi's predicted price: 3067 CNY
Bitstamp's predicted price: 488 USD





[ Plot legend ]

Today's data point was not bad (S = 0.0049 W = 0.614), and above the previous trend line, but not by much (by 37 CNY).  It seems still valid to use a straight-line trend, fitted by weighted least squares to the last six points, Apr/19--24.  Namely, A + B*(d-d0), where d-d0 is the number of days since Apr/19, A = 3138.67 and B = -12.01.

(The older data points should have their weights reduced when fitting the trend, but the effect on the prediction would have been small.)

The Bitstamp prediction, as usual, is the Huobi prediction divided by the currency conversion factor R, which was assumed to be 6.29 CNY/USD. It was 6.30, 6.28, 6.34, 6.27, 6.25, 6.26 at the last five Slumber Times.
 
Checking the previous prediction

Prediction was posted on: Wednesday 2014-04-23, 21:47 UTC
Prediction was valid for: Thursday 2014-04-24, 19:00--19:59 UTC (~21 hours later)

Huobi's predicted price: 3059 CNY
Huobi's actual price (L+H)/2: 3096 CNY
Error: 37 CNY (~6 USD)

Bitstamp's predicted price: 487 USD
Bitstamp's actual price (L+H)/2: 491 USD
Error: 4 USD
 
NOTE: "I never think of the future.  It comes soon enough."  --Albert Einstein

谢谢！

Maybe.  But BTC-China lost almost all its volume after 2013/12.  Perhaps customers migrated to Huobi and OKCoin.
也许吧。但BTC-中国2013/12之后失去了几乎所有它的体积。也许客户迁移到Huobi和OKCoin。

Also, Huobi and OKCoin have no trading fees.  Therefore each customer will make more trade on Huobi and OKCoin than in other exchanges.
此外，Huobi和OKCoin无交易费。因此，每个客户将在Huobi和OKCoin比在其他交易所更多的贸易。

EDIT: fixed wrong quote.

From that paper's abstract:

Aha, I always suspected that 17 was not a prime.  Where do I get in line to buy a PQC (personal quantum computer)?