A Market 'Tell' That Works: Breadth and Depth (With a Twist)

Today, James from FreeTradePicks.com has put together a compelling article about how you can use volume to improve your trades. After you read it, he invites you to register for the FreeTradePicks.com newsletter to receive all of his updates.


For those of you who think the market does not drop hints about its next direction, don't be so sure. While the major indices do not send explicit telegrams as to their intent, some subtle clues can be gleaned if you just know where to look. We have found that careful study of breadth and depth is quite effective at spotting looming trend reversals.

What are depth and breadth? That is the brief way of describing the market's overall volume, and the number of advancing stocks versus the number of declining stocks (respectively). The former attests to the conviction (or lack thereof) of the market's moves, while the latter indicates whether or not the majority of the market's stocks are actually participating in the trends. Both are clearly requirements if a trend is to have longevity, but our analysis has a bit of a twist to it... to take the opinion and interpretation out of the equation.

Though breadth and depth data exists for the market at large, you will usually find the data in exchange-specific versions (NYSE, AMEX, or NASDAQ). Our preference is for the NYSE's data, though the NASDAQ's has back-tested successfully too.

The technique actually requires four data sets: bullish volume, bearish volume, the number of advancers, and the number of decliners for every single day in a timeframe. However, we don't use any of the raw data itself. We can't -- it is too erratic.

Rather, we use moving averages of the daily value for all four figures. This smoothes the data out into an indicator that's easy to use and interpret. More specifically, the moving averages highlight the trend of these four pieces of information. (Sorry, our moving average lengths are proprietary, but with a little experimentation, you should be able to figure out lengths that work well.)

What we're looking for are the points where the moving average of the two volume moving averages cross each other, as that generally pinpoints a switch in the market's overall volume trend; when the bearish volume average crosses above the bullish volume average, it's time to turn bearish.

In the same vein, when the moving averages of the advancers and the decliners cross one another, that too indicates a major shift in the market's underlying health.

The interpretation is the same for both bullish and bearish scenarios…crossovers of the moving averages also serve as signals.

Clear as mud? Don't worry, the graph below will clarify the idea for you.

What you're seeing is the S&P 500 in comparison to its breadth and depth data. As was mentioned a moment ago, we don't actually consider the raw daily data, since it's just too volatile to interpret. Rather, in the middle of the chart we've overlaid the moving average of the NYSE's decliners (red) on the same plot as the moving average of the advancers (green) for the NYSE. At the bottom of the chart we've overlaid a moving average of the NYSE's bearish volume (red) on the same plot as the moving average of the bullish volume (green) for the NYSE.

The "signals" occur when either or both sets of moving averages give us a crossover. Though we have pointed out two specific ones on the chart, there are actually several. Yes, some are errant; most are accurate though.

Simple to the point of being ridiculous? We can't argue that. On the other hand, it's a stunningly effective method at spotting reversals. And here's the really cool part -- it's not a coincidental or a lagging indictor... it's quite predictive.

When we fast forward to today, we can see something that most traders may not believe -- bullish breadth and depth. The market isn't just 'drifting higher' -- buyers really are flowing in, at least according to the trends indicated by both sets of moving averages. Obviously things change over time, but for right now the broad rally is actually something you can believe in. Nobody's more surprised than us, but we're not going to do an undisciplined thing like ignore the data that's right far more often than it's wrong.

Good Trading,

James, FreeTradePicks.com

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8 thoughts on “A Market 'Tell' That Works: Breadth and Depth (With a Twist)

  1. Marco, Breadth and depth analysis described in the article is very different from the triangles that MarketClub produces. As I understand, MarketClub's triangles are based strictly on the price action of the given instrument (stock, ETF, future, etc.) in the given time frame (daily, weekly, monthly). The triangles look at when price breaks through a level or resistance or support in the timeframe, and it appears, without regard to volume. The breadth and depth analysis looks at volume of advancers vs. decliners in a broad index--the only use of price is to determine whether individual stocks in the index advanced, declined, or remained unchanged for the day before the average is applied; it does not consider how far the prices advanced or declined. As mentioned in the article, this indicator is neither coincidental nor lagging--it is predictive, while the MarketClub triangles are coincidental. So breadth and depth analysis would be expected to give signals ahead of the move that the MarketClub triangles would give for the index. Also, breadth and depth analysis is on a broad index, so it would indicate likely moves in the index, which may or may not translate to same move in individual stocks, due to their specific issues.

  2. I've gone and compared those moments to volume as well... it is an interesting comparison that would be good for your readers to see, I think.


  3. We see many cross-overs on this chart. Why do you only pick one buy and sell arrow ? Maybe I do understand nothing, but would you be a little bit clear if not the aim of this writing is just raising curiosity ?

    1. Hi Emin - thanks for the question. Your guess is right.... our only goal with the article was to raise curiosity in the technique. We only picked one buy and one sell to show you an example or two of how it could be actualized. There are actually several buys and sells that would have been made from crossovers. We were just trying to simplify the chart.

  4. You didn't mention it but did your breadth and depth indexes give a buy signal late Oct-beginning Nov similar to the one you marked in July? Wouldn't it be more valuable if you had marked all the buy and sell signals on your chart? Are am completely misreading your charts.

    1. Hi Joe. Would it be more valuable to mark all the signals? Probably, though the chart would have been twice as big and impossible to look at (and still make any sense of). There would have been about ten buys or sells. we only showed two to illustrate the idea. Yes, there was a 'buy' in late October.... we just didn't mark it to keep the chart clean. An actual 'active signal' chart would have had - like I said - about ten signals in the span you see. The goal here was primarily to show how the premise worked, with a couple of examples.

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