Trading Articles
Article Categories
Article Tools

Probability (size) calculator
Updated May 14, 2022
trending_up
213 views
thumb_up
4 thanks given
group
3 followers
forum
5 posts
attach_file
0 attachments

Welcome to futures io: the largest futures trading community on the planet, with well over 150,000 members

Genuine reviews from real traders, not fake reviews from stealth vendors
Quality education from leading professional traders
We are a friendly, helpful, and positive community
We do not tolerate rude behavior, trolling, or vendors advertising in posts
We are here to help, just let us know what you need
You'll need to

register in order to view the content of the threads and start contributing to our community.

It's free and simple.
-- Big Mike, Site Administrator
(If you already have an account, login at the top of the page)

Probability (size) calculator

(login for full post details)

#1 (permalink )
Prague, Czechia

Experience: Intermediate

Platform: Sierra Chart

Broker: Sierra Data

Trading: GBL

Posts: 33 since Jan 2019

Thanks: 2 given,
18
received

Hello forum,
I'm looking for a calculator for position size based on probability of success on specific strategy.
I need to know what's the probability of let's say 10 losses in raw if strategy have 40% success rate.
Does someone knows that kind of tool?
Or maybe excel formula ?
Thanks

Can you help answer these questions from other members on futures io?

Best Threads (Most Thanked) in the last 7 days on futures io

(login for full post details)

#2 (permalink )
Nashville, TN

Experience: Beginner

Platform: NinjaTrader

Broker: NinjaTrader, Continuum Data

Trading: MES for now... baby steps

Posts: 272 since Feb 2022

Thanks: 194 given,
497
received

kremat0r
Hello forum,

I'm looking for a calculator for position size based on probability of success on specific strategy.

I need to know what's the probability of let's say 10 losses in raw if strategy have 40% success rate.

Does someone knows that kind of tool?

Or maybe excel formula

?

Thanks

Not exactly what you're asking for, but risk of ruin helps you determine what your position size should be.
https://2ndskiesforex.com/risk-of-ruin-calculator/
With that, you plug in the position size to determine risk of ruin rather than it telling you your position size. There's probably a risk of ruin calculator somewhere that will do that.
This link discusses the different formulae for calculating risk of ruin. You could use that in excel. https://tradingtact.com/risk-of-ruin/

The following 2 users say Thank You to chipwitch for this post:

(login for full post details)

#3 (permalink )
Prague, Czechia

Experience: Intermediate

Platform: Sierra Chart

Broker: Sierra Data

Trading: GBL

Posts: 33 since Jan 2019

Thanks: 2 given,
18
received

Thank you for you help
It wont help me, because Im developing a strategy without fixed profit in tick.
Target is hit in 40% trades, RR seems to be something around RR 1/2.2
In half year back test longest loosing streak was 6 times in row.
I just want to know probability to set proper size.

(login for full post details)

#4 (permalink )
Nashville, TN

Experience: Beginner

Platform: NinjaTrader

Broker: NinjaTrader, Continuum Data

Trading: MES for now... baby steps

Posts: 272 since Feb 2022

Thanks: 194 given,
497
received

kremat0r
Thank you for you help

It wont help me, because Im developing a strategy without fixed profit in tick.

Target is hit in 40% trades, RR seems to be something around RR 1/2.2

In half year

back test longest loosing streak was 6 times in row.

I just want to know probability to set proper size.

Oh! I misunderstood! That will depend on the number of trades you do. The more trades you do, the higher the probability of getting 10 losers in a row. Here's a pretty good link I think you're looking for: https://www.winningedgeinvestments.com/posts/the-mathematics-runs-of-outs-or-losing-streaks

(login for full post details)

#5 (permalink )
Albuquerque, NM, USA

Posts: 124 since Jul 2012

Thanks: 87 given,
114
received

kremat0r
Thank you for you help

It wont help me, because Im developing a strategy without fixed profit in tick.

Target is hit in 40% trades, RR seems to be something around RR 1/2.2

In half year

back test longest loosing streak was 6 times in row.

I just want to know probability to set proper size.

I haven't used this, but had it bookmarked:
https://www.daytradinglife.com/trading-spreadsheets/losing-streak-probability-calculator/

The following user says Thank You to ondafringe for this post:

(login for full post details)

#6 (permalink )
Prague, Czechia

Experience: Intermediate

Platform: Sierra Chart

Broker: Sierra Data

Trading: GBL

Posts: 33 since Jan 2019

Thanks: 2 given,
18
received

ondafringe
This looks good, I need to play with it.
Thanks!

The following user says Thank You to kremat0r for this post:

Last Updated on May 14, 2022

Ongoing