And that is the (non)answer that I get whenever I ask that question in this forum. I had to ask the same person three times (on another thread), before he understood the question (and answered it for only one special case).

Well, I am not sure where the similarity is...

I have no opinion on bitcoin as an abstract distributed algorithm.  As a concrete activity/institution, different people want/hope it to be very different things.  I find some of those things laudable, some quite wrong, but all rather unlikely to succeed.

Interesting analysis!

It may be interesting also to compare the distribution of trade sizes at other periods in the past, e.g. a couple of days around May/15 (the lull before the 400->600 rally), Feb/19 (a period of steady decrease), Feb/03 (the New Year holiday week), etc.

Well, if you ever have to do some accounting yourself, over ledgers spanning several years of transactions, you would appreciate this principle.

If the totals from two ledgers (say, bank statements and invoices) don't match as they should, even by a few cents, you must check everything all over again because it may be due to some arbitrarily large error on your part (like using the wrong invoice with a similar price), or by someone who was trying to doctor the books. You can waste a lot of time that way.

Or, suppose that you get the monthly report of you bank account for June, and the starting balance is 1.27$ less than the final balance in the May report.

Few joys in life compare to that of having the financial report of one's research project approved by the funding agency's accountants.   Not even that of having the project's funding approved in the first place.  

Why list BTC-China and not any of the other Chinese exchanges? 

Huobi (BTC:CNY ~20 kBTC/day currently, got to ~350 kBTC one day) is carried by Bitcoinwisdom

OKCoin (BTC:CNY ~30 kBTC/day) by Bitcoinwisdom and Bitcoincharts.

LakeBTC (BTC:USD ~2kBTC/day) by Bitcoincharts

There may another 2-3 Chinese exchanges that are not reported by either chart site.

AnxHK has several currency pairs in Bitcoincharts ~0.6 kBTC/daily, but this may be the sum for all currencies rather than for each currency.

Well, for example, if they fixed the account balances without entering the fix as a trade, any auditing program that tried to validade the balances against the trade log would have to read a separate file of hand fixes and merge them with the trades. 

In accounting it is standard practice to correct past mistakes on an active ledger by entering a new transaction at the date of the fix, rather than going back and trying to modify the wrong entries.  The latter could cause unbounded trouble and waste of time if anyone got a copy of that ledger, or copied any data from it (such as day totals), before it was modified.

indeed.  And the order book activity is even worse.  I have noticed that, immediately after a "real" sale that lowers the bottom of the spread, some robot immediately sprays a bunch of tiny orders into that gap, most of them spaced 0.01 CNY apart; and soon afterwards it sucks up half of those orders and posts a few more above them.  Ditto after a "real" buy, at the other end of the spread.

At MtGOX, sometimes one could see a robot (not "Willy") making a tiny trade every minute or less, alternating between the two ends of spread.  At OKCoin instead there used to be lots of tiny trades at random prices within the actual spread.

The smallest legal division of the yuan is 0.01 CNY.  I have not seen any orders on Huobi with prices which are not multiples of that.  Perhaps the price on the order book display can be trimmed to two decimals instead of four?

Also, on the order book display, it is not immediately obvious whether the blanked-out integer part of a price is the one below or the one above.  Would it be better to print in full, graying out the leading digits that are equal to the ones above AND below them?  Namely, instead of

3872.9000 0.7801
     8900 0.0010
     8400 0.8240
     6000 0.2990
     1400 0.3000
     0100 0.6883
     0000 3.2277
3871.0200 0.0020
     0100 0.0020
     0000 1.3114
3870.8600 0.2970
     1500 5.0000
     1100 5.0000
     1000 5.9800
     0000 20.538
3868.8000 0.0500

display

3872.9000 0.7801         3872.90  0.7801
3872.8900 0.0010         3872.89  0.0010
3872.8400 0.8240         3872.84  0.8240
3872.6000 0.2990         3872.60  0.2990
3872.1400 0.3000         3872.14  0.3000
3872.0100 0.6883         3872.01  0.6883
3872.0000 3.2277         3872.00  3.2277
3871.0200 0.0020    or   3871.02  0.0020
3871.0100 0.0020         3871.01  0.0020
3871.0000 1.3114         3871.00  1.3114
3870.8600 0.2970         3870.86  0.2970
3870.1500 5.0000         3870.15  5.0000
3870.1100 5.0000         3870.11  5.0000
3870.1000 5.9800         3870.10  5.9800
3870.0000 20.538         3870.00  20.538
3868.8000 0.0500         3868.80  0.0500

Well, those COULD be trades injected by hand to correct recent mistakes -- not necessarily software bugs, but things like fees charged to the wrong account, trades that were mangled by the API going offline, whatever.  For example, say that the management reviewed a client's complaint and agreed that he SHOULD have had his 1.9629 BTC bought or sold at 3930.51 CNY on July 6.  So they entered that trade by hand now, jumping over the order book, since it would be the cleanest way to satisfy the client without breaking all their other accounting and auditing software.

(Did I tell you this story of a friend of mine? Back in the 1960s or 1970s, when people here paid their utility bills at the bank, his parents got an astronomical water bill due to a faulty water meter.  The water company readily admitted the mistake, but gave them an astronomical cashiers's check that they could use only to pay that astronomical bill at the bank --- because "the computer system did not allow fixing the error in any other way".)

It may be; seems hard to tell.  (I would think that day traders (should we call them "minute traders" in the case of bitcoin?) will want to keep all their speculation budget in the exchange, in spite of the risk, since they may need it without prior warning and their revenue is proportional to the amount traded.)

A more important number is how much bitcoin is held by speculators who operate on the scale of days or weeks, rather than minutes.  Those traders probably keep their coins and money off-exchange, but will move them in if the price changes significantly.  Thus the walls at 800$ or 400$ may be a lot taller than what shows in the order books.

Is that correct?  AFAIK, only some merchants (like Overstock) opt to receive bitcoins directly.  Usually, when you buy "with bitcoin" through services like BitPay, they give dollars to the merchant and sell your coins at some exchange.  Didn't BitPay say that they used Bitstamp, specifically, some time ago?  Isn't Dell using such a service?

AFAIK the price on exchanges is the reference used for off-exchange deals, too.  Large amounts may be transacted somewhat above or below that price, depending on which side is more eager to make the deal, but not very far from it.  And, conversely, off-echange deals will "spill over" to the exchanges to some extent. (If you need 10'000 BTC and find someone eager to sell 12'000 at 10% below market, why not but them all and sell the extra 2'000 on exchanges?  Even if it will cause the market price to fall 5%, you will make a nice quick profit there.  Ditto if vice-versa.)

Well, Erik Vorhees did not like them: http://moneyandstate.com/reflections-right-privacy-response-nydfs-bitcoin-proposal/

"Arguing with a scammer" could be the perfect example for the dictionary definition of "pointless".

How do you send USD to Coinbase/exchange/Bitpay/whatever, and what do they send to Dell -- USD, or BTC?  If USD, how do they send it?

I would think that the proposed NY regulations for cryptocurrencies are bad news, that more than compensate for Dell "accepting bitcoins".  So perhaps one should ask why isn't the price falling now.

(Well, you know my explanation for that, and I know that you don't like it...)

Hard to imagine someone fleeing his home and risk being chased by the police for 2800 dollars.   Unless more instances turn up, I don't think it is reasonable to call him a scammer.

BTW, he once told us that his business is to buy old barn wood and sell it to decorators and other people who wnat a 'rustic' look.

You are ALMOST correct. 

Yes, that is where I have been doubling my BTC holdings every day since December, remember? 

Seriously, I told you my best guess for the cause of this mini-rally (or mini-bubble, whatever) that started on May 20 from ~450$; namely big Chinese traders buying bitcoin in order to move them to (Hong Kong based) BitVC, even before it opened.

However, the "sawtooth" shape of the plots, and the persistence in the ~610--620$ range, make me think that someone may be trying to keep the price stable, in spite of a general tendency to gradual decline.   Perhaps the Winklevosses and other fund owners, existent or planned, think that keeping the price stable will help convince the SEC to allow the sale of Bitcoin funds to Americans?  (But such manipulation would probably cost a lot of money, and it seems that the upwards "pushes" are led by China...)

Wow, thanks!

Actually they do, and are amazingly open about it.  They take checks to the bearer and somehow launder them.  That must be one of the things that they learn in their 7 years of school, that we engineers don't get to learn in our 5 years. 

Yeah, here in Brazil MDs too have two prices, "with receipt" and "without receipt".  If you ask for a receipt you can deduct some of that expense when you file your taxes --- but then he too has to declare that income when he files his taxes, because the Brazilian IRS is likely to do a cross-check.