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Question |
Where can I find more information on the Market Playback
feature of Investor/RT? |
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Answer |
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Market Playback
Video Demonstration
Investor/RT offers a comprehensive Market Playback (replay) feature.
Tick data and/or bar data for one or more instruments can be replayed
into your Investor/RT workspace at a user specified playback rate
(actual, 2x, 10x, 20x, etc). The Playback feature operates with all
dynamic Investor/RT window types including Traditional Charts, Market
Profile Charts, Footprint Charts, Point and Figure/TLB Charts,
Quotepages, Portfolios, Time and Sales windows, and others. Playback is
initiated by choosing File-->Playback to open the Playback Control
window. This window serves both as a toolbar for controlling the
playback and as the setup window where you specify the ticker symbol or
the name of a quotepage containing a list of symbols to be replayed in
concert.
The playback speed is specified by indicating how much data is to be
played back for each second. To playback in realtime, specify "1 second
equals 1 second". To playback at 10x (ten times actual) speed, specify
"1 second equals 10 seconds". A setup of 1 second equals 1 minute gives
you 60x realtime playback. For convenience you can specify playback
rates in seconds, minutes, hours, or even days for end-of-days users
playing back daily bar charts. If you typically trade using Market
Profile or tick per bars charts you will want to use the seconds,
specify 1 second equals N seconds to set the speed at N times actual. If
you typically trade with 5-minute or 13-minute interval charts, set the
playback speed to 1 second equals 5 minutes, or 1 seconds equals 13
minute to pace the playback. Playback speed is dynamically adjustable.
The rate that ticks are fed into the workspace changes immediately as
you modify the numbers or units in the playback window. When you open
the playback window, the settings you used the last time will appear.
A disclosure arrow at the upper right of the Playback window allows you
to collapse the window into a toolbar during playback; click the arrow
again to expand the window to adjust setups. When collapsed during
playback the window shows only the simulated time of day and the
playback button controls.
During playback, you can start over by clicking the button at the far
left side of the playback toolbar. All toolbar buttons offer help hints
as you point at them if you have the button help option turned on. You
may pause playback at any time, make chart adjustments, open/close
windows, then resume playback; the tick data replay will resume where
you left off. It is not necessary to pause playback to open new charts
or other windows. During playback you can do just about anything you can
do with the software during normal real-time usage. Just keep in mind
that the software is using the current playback time instead of the
actual time of day to govern its behavior. Thus when you open a new
chart, it will load data up to the current simulated time of day and
begin updating tick by tick from there with the playback data.
There is no limit to the amount of time you may playback. Simply specify
the date and time that playback is to begin using the date/time control
in the playback window. When playing back multiple symbols, Investor/RT
will load data for the requested period for all symbols in the
user-specified quotepage. Tick data is fed into the Investor/RT
workspace in proper time sequence to provide a realistic simulation of
many symbols trading in concert.
Market Playback works best if you have tick data on file for the
symbol(s) you wish to playback. If you have only one-minute bars on file
you should use a higher playback speed (e.g. 1 sec equals 30 or 60
seconds; 30x or 60x). This will give you a new one minute bar every 1 or
2 seconds. Playback requires that you stop the real-time data feed
before playback can begin. Typically, you will be using playback after
market to review the just completed trading session. If your Historical
Data preferences are setup to retain zero days of tick data, the ticks
for the completed trading session will have been eliminated to form one
minute bars on the database. See Setup: Preferences: Historical Data and
adjust your tick data retention to the number of days that you will
typically wish to playback. This will ensure that tick data is retained
for playback after the trading session ends. Investor/RT can playback
either minute interval data or tick data or any mixture of the two. For
example, if you have the last 2 days of ticks and 30 days of longer term
one-minute bars, a playback of the last 10 days will playback 8 days
using the one minute bars followed by the most recent two days of tick
by tick data.
Investor/RT uses the time stamp of each bar or tick to pace the playback
at the requested speed. Users of DTN IQFEED know that DTN at present
supplies time stamps only to the hour and minute. Investor/RT playback
takes this deficiency into account by equally distributing the ticks for
each minute interval. So for example, if you have 300 trades during a
one minute period, playback will play the ticks back at the rate of 5
per second during that interval. We have been advised by DTN that IQFEED
will begin reporting trading times to the hour/minute/second on or about
April 1, 2007. Once this DTN improvement goes into effect, the actual
second resolution time stamps will be used during playback.
During playback, the heartbeat icon on the main toolbar (far right)
changes to the green "start playback" icon to indicate that the data
feed is off and playback is in progress. When you click the playback
window's pause button, the heartbeat changes to either the red X or the
working offline icon to indicate that the system is idle, not connected
to the feed and playback is not active.
Multi-Session Playback
When playing back multiple trading sessions of data, the playback window
advances and displays the date and time of day at the top of the
playback window. When the end of a trading session is reached, the
simulated time continues to progress, but no data is played for the next
trading session until the playback clock reaches the opening time of the
next trading session. For a day session, e.g. one that closes at 4:00 pm
and does not open again until 9:30 the next morning, this could take
awhile, depending on the playback speed you have selected. The playback
window provides a simple way to "advance" past this "session closed"
period of time: just click the green start button and playback will skip
forward to the date/time of the next available tick and proceed from
there at the user specified playback speed.
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