Thursday, October 05, 2006

TIKI (Dow TICK) and Program Trading

Let's say that, instead of measuring the number of NYSE stocks trading at their offer prices vs. those trading at their bids (NYSE TICK), we simply focus on the Dow 30 Industrial stocks and investigate how many of them are trading bid vs. offer. The resulting statistic is called TIKI and, it too, can be viewed as a sentiment measure. When Dow buyers are aggressive, they will be willing to transact at the stocks' offer prices, and you'll see TIKI values skyrocket above +20. When Dow sellers are aggressive, they're willing to bail out at the stocks' bid prices and TIKI will plunge below -20. Because the Dow stocks are quite liquid and trade frequently, the TIKI moves much faster than the NYSE TICK. Its values are also distributed very differently from the TICK; TICK and TIKI correlate significantly (around .60), but hardly perfectly. The majority of variance in TIKI cannot be explained by the general buy/sell sentiment captured by TICK.

The reason for this is that TIKI is highly sensitive to program trading. Whenever a program is executed that calls for the simultaneous buying or selling of a basket of stocks (arbing stocks against index futures would be a common example), TIKI values will shoot very high or very low. The Dow stocks, being liquid, are frequent components of such stock baskets. When the Dow stocks move in unison, it is often because programs are being set off.

One way we know this is by looking at the distribution of TIKI values on a 10 second basis. (Yes, I archive those data also). The odds of a very high number of Dow stocks upticking or downticking at exactly the same time should be quite small if we assume that there is an even probability of the next tick being an uptick or downtick in each issue. What we see, however, is many more extreme values than would be predicted by chance. These bulges at the extreme are the result of systematic buying and selling by institutions, often as part of arb (non-directional) trade.

If you get that idea, then it will make sense to you that absolute TIKI values are not especially helpful in gauging the sentiment of the market. TIKI can soar or plunge, simply because institutions are buying or selling stocks at the same time that they sell or buy index futures. It is the correlation between TIKI and price that is crucial. When TIKI hits extremes and price is moving in a correlated fashion, we know this is part of directional trade--not arb.

So let us take a moving correlation between TIKI and price change in the S&P 500 Index (SPY). I have cumulated each day's TIKI values, adjusted them for a zero mean, and correlated TIKI and daily price change over a moving 10-day window going back to 2004 (N = 682 trading days).

The average 10-day correlation between daily TIKI and daily price change in SPY over this period has been .63. When we have a strong TIKI/price correlation (above .80; N = 108), the next ten days in SPY average a gain of .73% (73 up, 35 down). That is significantly stronger than the average 10-day price change in SPY of .26% (397 up, 285 down).

When the TIKI/price correlation is relatively low (below .50; N =133), the next ten days in SPY average a loss of -.41% (57 up, 76 down). That is significantly weaker than the average 10-day performance.

What this suggests is that, when TIKI is well correlated with price, the market tends to outperform. When TIKI is poorly correlated with price, the market tends to underperform. This pattern, I have found, is also present at intraday time frames. A reasonable explanation for the findings is that low correlation periods represent occasions of high program/arb trading, whereas high correlation periods represent periods of high directional trade.

We last saw very high TIKI/price change correlations on September 21 and 22, when the values were about .88. The recent price strength has followed from that. We are now at relatively average levels of correlation (.60). Much of May and June--a period of correction--featured very low correlations.

According to H. L. Camp, about 45% of all NYSE volume is now attributable to program trading. The buying or selling you see on the screen may or may not reflect genuine demand or supply in the marketplace. Who is in the markets ultimately impacts what markets do.

14 comments:

James said...

Brett,

Where do you get the data feed for the Tiki and Tick? I'd like to maybe experiment with these measures myself.

best to you,

james

Brett Steenbarger, Ph.D. said...

Hi,

I have two real time data feeds: Townsend RealTick and e-Signal. Most real time feeds carry those indicators, but there can be some variance among feeds, especially re: the TIKI.

Brett

meblogin said...

Fascinating reading...thank you

Brett Steenbarger, Ph.D. said...

Thanks for the note. This is, IMO, one of the most promising areas of market research.

Brett

Yossi said...

Hello Brett,

would you please explain the purpose and techniques of "I have cumulated each day's TIKI values, adjusted them for a zero mean"

Thanks

Brett Steenbarger, Ph.D. said...

Hi Yossi,

It's really just a convenience. I just do a little data transformation to create a mean value of zero for the time series. That way, it's easy to see that positive readings are stronger than average; negative values are weaker. My data series consists of one minute hi-low-close values.

Brett

Bert Hancock said...

Hi again, Brett;

Regarding the subject of arb trading (though I may not understand it perfectly), a question follows: Some have speculated that the more sophisticated and active automated trading programs become, the less and less opportunities to make money (short-term, I suppose) there will be. Rationale goes on to say that any tradeable price patterns/behavior will quickly be absorbed, so that one's "edge" dissipates too rapidly to really benefit from.

How do you see this concern?

Thanks a lot, as always,
Bert

Brett Steenbarger, Ph.D. said...

Hi Bert,

IMO, automated trading in size close to the market has all but eliminated the scalping business for discretionary traders in the equity index futures markets and in most fixed income futures. It has forced very short-term traders to either move to different markets or to widen their time frames.

Brett

Bert Hancock said...

Thanks for your prompt answer, Brett.
Do you see automated trading (or other methods) somehow rendering longer time frames dramatically less profitable too, at some point?

Brett Steenbarger, Ph.D. said...

Yes, it has already lowered the volatility and decreased the trending behavior in the stock indices, reducing overall opportunity for momentum and trend-based traders.

Brett

Bert Hancock said...

I believe I've read your work citing that very fact, come to think of it. If that's a tendency we can, at least, generally expect to play out into the future, then it seems to lend toward trading the smaller-cap stocks even more.

It's probably too much to be concerned that this could inevitably lead even to those being difficult to trade sometime into the future(?)

Fantastic site of yours, btw--the best I've found out there.

Brett Steenbarger, Ph.D. said...

Hi Bert,

I do think the growing popularity of sector ETF and indices will lead to more arb and pairs trading and make common trend/momentum trading more difficult. On the other hand, there are countertrend strategies that work pretty well in such environments if you can ride out the noise close to the market. Note that many of the patterns I research in the market where I find an edge pertain to 3-5 day holding periods. Much of that directional edge has been occuring between the market close and the next day's open.

Thanks for your kind feedback--

Brett

Gary said...

Hi,

Yet another interesting subject at this fine site.

Bert - I found lots of info at this site:

http://www.indexarb.com/

Hope this helps - Thanks

Brett Steenbarger, Ph.D. said...

Thanks, Gary, for passing along the link--

Brett