NexusFi: Find Your Edge


Home Menu

 





backtesting look ahead bias vs lag


Discussion in Traders Hideout

Updated
    1. trending_up 1,071 views
    2. thumb_up 3 thanks given
    3. group 4 followers
    1. forum 2 posts
    2. attach_file 1 attachments




 
Search this Thread
  #1 (permalink)
 bp2012 
Pittsburgh, PA
 
Trading: Forex
Posts: 8 since Sep 2012
Thanks Given: 8
Thanks Received: 4

Hi,

Is anyone aware of a backtesting framework that supports multi-timeframes without either unnecessary lag by using the last complete bar or introducing look forward bias by using a complete bar that has data from the future?

For example, a backtest is iterating through 5m bars and is currently evaluating the bar at 03:45am. Any 5m indis would be calculated as of the close of that bar. But let's say you wanted to also evaluate against indis at a higher timeframe such as the 1 hour. Evaluating the prev complete 1hr bar (2am) would result in excluding action after 3am (unnecessary lag.) Using a complete 1h bar at 3am would include data from 03:50 through the end of the hour which doesn't yet exist at the end of the 03:45am bar (look forward bias.)

Ideally, any multi-tf indis would use a partially complete bar on the right side to simulate what we'd actually be seeing in real time if we went back to that point in time. So in this case it would be the incomplete 1h bar that is painted at the same time as the 3:45am 5m bar.

Hopefully this question makes sense.


Started this thread Reply With Quote

Can you help answer these questions
from other members on NexusFi?
Hungary Called for Magyar at 97pct, Ending 16-Year Orban …
Prediction Markets & Event Contracts
Kraken Becomes First US Digital Asset Bank With Direct F …
Cryptocurrency
Ripple Prime Joins Nodal Clear as Clearing Member -- $3 …
Cryptocurrency
Day 96 Missiles Hit Kuwait and Bahrain: June 15 Peace at …
Prediction Markets & Event Contracts
Five Days Until the Gap Dies -- CME Goes 24/7 on All Dig …
Traders Hideout
 
Best Threads (Most Thanked)
in the last 7 days on NexusFi
Sober Journey With S&P
24 thanks
2026 Jlab journal
10 thanks
Algo automated / semi-automated trading anyone?
6 thanks
Lady Vols Primer: Trading Volatility Journal
6 thanks
Trying to learn Volume and price action correlation
5 thanks
  #2 (permalink)
 
trendisyourfriend's Avatar
 trendisyourfriend 
Quebec Canada
Legendary Market Wizard
 
Experience: Intermediate
Platform: NinjaTrader
Broker: AMP/CQG
Trading: ES, NQ, YM
Frequency: Daily
Duration: Minutes
Posts: 4,580 since Oct 2009
Thanks Given: 4,266
Thanks Received: 6,199


bp2012 View Post
Hi,

Is anyone aware of a backtesting framework that supports multi-timeframes without either unnecessary lag by using the last complete bar or introducing look forward bias by using a complete bar that has data from the future?

For example, a backtest is iterating through 5m bars and is currently evaluating the bar at 03:45am. Any 5m indis would be calculated as of the close of that bar. But let's say you wanted to also evaluate against indis at a higher timeframe such as the 1 hour. Evaluating the prev complete 1hr bar (2am) would result in excluding action after 3am (unnecessary lag.) Using a complete 1h bar at 3am would include data from 03:50 through the end of the hour which doesn't yet exist at the end of the 03:45am bar (look forward bias.)

Ideally, any multi-tf indis would use a partially complete bar on the right side to simulate what we'd actually be seeing in real time if we went back to that point in time. So in this case it would be the incomplete 1h bar that is painted at the same time as the 3:45am 5m bar.

Hopefully this question makes sense.

With Ninjatrader you can tell your indicator to get updated OnBarClose which means once at the close of the bar. OnEachTick means on every single tick. OnPriceChange means once for each price change. This way you can eliminate what you call unnecessary lag by using the last completed bar.

https://ninjatrader.com/support/helpGuides/nt8/calculate.htm

Here is a screen capture of the ES today 1 min chart using 2 EMA of the same length (20) where the large one is on bar close and the other on each tick. As you can see, there is no need for a multi-timeframe chart configuration.


Reply With Quote
Thanked by:
  #3 (permalink)
 bp2012 
Pittsburgh, PA
 
Trading: Forex
Posts: 8 since Sep 2012
Thanks Given: 8
Thanks Received: 4


Thanks very much for the response and especially the link to the help files. There is a section on dealing with multiple timeframes that talks about the Calculate.OnEachTick property.

It's not an exact fit for what I was searching for, but fairly close. It certainly beats having to code everything myself.


Started this thread Reply With Quote
Thanked by:




Last Updated on May 26, 2023


© 2026 NexusFi®, s.a., All Rights Reserved.
Av Ricardo J. Alfaro, Century Tower, Panama City, Panama, Ph: +507 833-9432 (Panama and Intl), +1 888-312-3001 (USA and Canada)
All information is for educational use only and is not investment advice. There is a substantial risk of loss in trading commodity futures, stocks, options and foreign exchange products. Past performance is not indicative of future results.
About Us - Contact Us - Site Rules, Acceptable Use, and Terms and Conditions - Downloads - Top
no new posts