After recently stabilizing and then rising by about 15%, Chinese stock markets gave up half their gains overnight, causing worry in global financial markets.

For what it’s worth, given that I don’t follow the mainland Chinese stock markets carefully, this is what I think is going on.

Three important factors:

–a government crackdown on real estate speculation has shunted tons of “hot” money into stocks

–Beijing didn’t pay much attention to direct and indirect margin trading ( indirect meaning commercial loans collateralized by stocks bought with loan proceeds, which avoid the letter of the law), thereby allowing speculators to leverage themselves very highly

–stock market rules set limits on the daily movement in individual stocks to + / – 10%.  The way this works is that the exchange attempts to set an opening price at the start of the day.   Let’s say yesterday’s close was 100.  The exchange sees there are sellers at 100 but no buyers.  So it waits a little while and then moves the proposed opening to 99.50. Again sellers but no buyers.  So it moves the proposed opening to 99.  Same thing.  So the proposed opening price continues to ratchet down either until buyers emerge or the proposed price reaches 90.  In the latter case, the price remains at 90 until either buyers appear or the trading day closes.  The same process happens the following day.  (Of course, there might be overwhelming upward pressure as well, in which case the price ratchets up without trade, or stocks might trade–as appears was the case overnight–for part of the day before reaching the daily limit price.)

snowballing downward pressure

A big problem with the daily limit system is that in times of stress often no selling gets done.  For speculators who get margin calls, this means that each day the amount they owe their broker rises (as the market falls) and they can’t take any action to stop the bleeding.  So a horrible sense of panic comes into the market.

The resulting downward spiral is what Beijing was trying to fix when it initiated extraordinary market stabilization measures a short while ago.

The first step in recovery is to stop the market decline.

The second–which is where we are now, I think–is to begin to unwind the enormous margin position that Beijing inadvertently allowed to develop.  The only way to do this is to gradually withdraw the official props under the market, not enough to have the market freeze up again but enough to allow selling to happen.  My guess is that this is what is starting to go on now.  The keys to watch are volume figures and the total value of transactions–the higher, the better.  Unfortunately, I can’t volume figures for today’s trade anywhere.

effects?

In my experience, most emerging stock markets have problems like this in their early days.  Once the crisis is over, authorities usually pay better attention to margin debt.  Invariably, they effectively dismantle the daily limit rule.

Typically, stock market problems have no overall negative effects on the economy.

In the short term, however, margin or redemption selling can create perverse market signals.  Forced sellers liquidate what they can, not necessarily what they want to.  This means, for example, that Hong Kong stocks can come under pressure.  It also suggests that smaller, low-quality stocks may outperform blue chips–the former will be suspended while the latter go down.

This can be a real disaster for margin speculators, who may be left with an account that technically has equity in it but is filled with unsalable junk.  On the other hand, the forced nature of a margin-related selloff can give new entrants a chance to buy high-quality stocks at distressed prices.

One seemingly odd sign that the worst is over will be a collapse in smaller stocks as larger ones are beginning to rise again.  This means that buyer interest is returning to the smaller ones and they’ve resumed trading, which is a much better state than they’re in today.

Another, perhaps lagging, indicator that the worst is over would be Beijing ending the daily trading limit rule.

How long will the cleansing process take?

I don’t know enough detail to have an educated guess.  A couple of months would be my initial estimate.