To test a diagnosis, it helps to remove the suspected infectious agent. Something like this is now happening in the markets.

This is the first of five straight days when Chinese and U.S. stock markets will not be open on the same day. China closed Thursday and Friday for its annual military parade and commemoration of World War II’s end. Then here we head into the three-day Labor Day weekend.

So for two sessions, American stocks won’t be exposed to the Chinese market that so many consider toxic, and we’ll see if the inconclusive bounce and choppy positioning can tell us anything about whether this has been a brief market gut check or a long-lasting syndrome that threatens the bull market itself.

The S&P 500 (^GSPC) has regained only about a third of its losses, which is arguably the minimally acceptable rally off such an intense, almost vertical drop.

Let’s be clear that China has probably received far too much blame for the ugly setback in U.S. stocks. It’s more likely been a confluence of concerns that built into a dam break starting a few weeks ago:

Slow-motion crash in emerging market stocks and currencies, sloppy Chinese government treatment of the stock and currency markets, anxiety about how the Fed will act and the upending of big-money strategies meant to “manage” volatility.

China, in other words, is a badly insufficient excuse for what we’re seeing across the markets. Many noted that U.S. regional banks, biotechs and electric utility stocks, with zero China exposure, were crushed in the Tuesday selloff. This is true. And it just shows we’ve seen across-the-board selling pressure and an instinct to pare back investment risk.

The technical analysts who try to decipher the markets through charts tend to be handed a megaphone in fast-shifting markets like this one. They are now fixated on these questions:

-Does last week’s market low, about 4% down from Wednesday’s close, need to be “retested?”

-Did the indiscriminate, heavy selling of Tuesday, along with last week’s urgent dump, represent capitulation by the bulls, which often accompanies a market bottom?

-Can the market regain enough ground quickly enough to rescue the longer-term trend, which technicians portray as badly broken?

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The typical investor looking to accumulate stocks slowly for long-term purposes can easily ignore such talk and welcome the discounts created.

But those who care about the immediate path ahead are in some suspense, because at this stage of a market retrenchment, a sharp but fleeting correction that will be recouped within weeks or months looks pretty similar to what the beginnings of something nastier, such as a cyclical bear market. All the historical studies and technical models right now basically say: "If it's still a bull market, you want to buy them here. If not, then watch out." Thus the daily market argument in the form of rapidly bounding and rebounding prices. 

Longtime market diviner Louise Yamada, indeed, is quite concerned that this is where we’re at, and this possibility should at least be borne in mind.

All that said, let’s look at a few of the areas that were sending warning signals for months that stocks ignored until quite recently.

-Junk bonds: Yields on risky debt had been rising ominously since late June or so and accelerated higher in a worrisome way into August. But some comfort can be taken in the fact these risk spreads have retreated a bit in the past ten days. They are, at least, not dragging stocks to a worse place just yet.

Merrill Lynch bond strategists similarly said this week that stocks have weakened at least enough to price in the softer conditions in investment-grade credit, too.

-Emerging markets stocks have at least quit making new lows in the past couple of days, though they remain under heavy pressure. Have they fully priced in a possible Fed rate hike? Would that even hurt at this point given the dollar has not been as strong? Hard to call.

-Small-cap stocks have outperformed the S&P 500 over the past week or so. Again, it’s probably good to see as they’re a proxy for domestic economic growth and risk appetites. Helpful , but not decisive.

-Finally, the CBOE S&P 500 Volatility Index (^VIX): This gauge of volatility remained too elevated coming into this week to sound an all-clear signal.

It’s still a bit higher than the bulls would want to see, owing in part to those haywire volatility-fund machinations. But Wednesday’s sharp five-point drop was welcomed by the bulls as tentative evidence that the market is trying to restore homeostasis.

Now we’ll see if these vital signs improve at all in the absence of China’s direct daily influence.

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