Wednesday, August 19, 2009

Trusting Market Moves: Why Relative Volume is Important

In past posts, I have described a measure called relative volume, which looks at the current volume at a given point in the day and compares that to the normal, expectable volume at that time of day.

The idea is to see whether the market is unusually active or not. Significant variations in relative volume give us a clue as to whether large, institutional money managers are active in the markets. If so, they may be repricing assets, leading to possible trending moves. If the institutional money is relatively absent, we're more likely to see choppy and range markets dominated by market makers, algorithmic programs operating close to the market, and prop traders.

Let's take this morning as an example. After significant overnight weakness, we saw strong buying interest right from the market open, as noted in the intraday tweets. Volume in the S&P 500 e-mini (ES) futures for the first half hour was about 268 thousand contracts, not quite one standard deviation above the median volume for the first 30 minutes of trade. That is very healthy volume for a morning of very light economic news.

Seeing the solid volume coming into the market in response to weakness, hold above the Monday lows, and persistently lift offers in ES tells us that money managers were perceiving value as we moved toward 975 in that contract. It's when we see above average volume participating in breakouts and reversals that we can most trust those moves, as they have the support of participants that are market movers.
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10 comments:

BalaB said...

We're clearly trading off the $USD - Candle for Candle.

Seeing same phenom. as yesterday. 1/3 'normal' bid / offer size. Of course this may be totally meaningless.

D TradeIdeas said...

Glad to read your emphasis on the importance of 'Relative Volume' in determining how trustworthy market moves really are.

It's the bedrock of much of our analysis at Trade-Ideas as you know. We express the concept as a ratio, placing the current accumulated volume up to any given point in the day over the historical average volume of the same period. A reading such as 1.5 means therefore that a particular issue is 50% above its normal volume. A reading of 7 means its trading 7x more than usual; and so on for readings of 0.6, etc.

Full definition here

BalaB said...

p.s. I hope its cool using the comment section for intra-day discussion.

zircon-212 said...

IMO not cool....keep it to yourself

sandp emini said...

Thank you as always Dr.

" Volume in the S&P 500 e-mini (ES) futures for the first half hour was about 268 million contracts"

Typo?
I see 83142 contracts ?

Brett Steenbarger, Ph.D. said...

Hi Sandp,

Thanks for the heads up; I corrected the typo: should be "thousand" not "million" contracts. I think your data may need rechecking as to the actual ES volume.

Brett

Brett Steenbarger, Ph.D. said...

Hi David,

Great point; it's an excellent feature of Trade Ideas--

Brett

Matt Fahmie said...

The significance of understanding the how the market is facilitating trade through relative volume is one of the cornerstones of my trading.
Another important aspect to understand with volume is how vertical volume will effect the speed of price movement.

BalaB said...
This comment has been removed by the author.
Satish said...

Don't they(instituitions) hide volume in stocks using darkpools?