A losing streak is multiplication, not a cue to size up
Independent losses multiply. They do not mean the next ticket is owed a larger size.
Direct answer
How do you calculate the chance of consecutive losing trades? You multiply the per-trade loss rates, under the assumption you actually wrote down. If each sitting is independent and your written loss rate is 40%, five losses in a row is 0.4⁵ = 1.024%. That number is a product. It is not a cue to add size on the sixth ticket.
I do not have a BarionQuant practice log on this page with “last fill time + next lot.” Without that log I will not paste a position ticket. The older size-after-a-loss brief stays postponed. Size still belongs after invalidation: Invalidation before size.
The product, written out
Assume five sittings, each independent, each with a 40% chance to lose under the rule you wrote. The joint chance of five losses is:
| Streak length | Product at 40% per sitting |
|---|---|
| 1 | 0.40 |
| 2 | 0.16 |
| 3 | 0.064 |
| 4 | 0.0256 |
| 5 | 0.01024 (1.024%) |
I use 40% because a written 1:1 method with more losers than winners is common. I do not claim our desk printed 40%. Five coin-flips (50%) would be 0.5⁵ = 3.125%. Do not mix those two products.
The point of the table is the shape: each extra loss is another multiply, not “the market owes a winner.”
If the sittings are not independent — same session, same size, same unfinished idea — the table does not apply. Then the honest line is “I repeated the same sitting,” not a probability.
What we do
After two losses I do not raise the next risk. I write the product, or I write “not independent — stop.” Then I either keep the same risk or I flatten the day. A daily loss limit is a size cap is the next rule.
BarionQuant Desktop is where I replay without seeing the right side. Free starts after sign-in on EURUSD. Standard is $15/mo or $150/yr; Pro is $29/mo or $290/yr. Windows. Not a broker. No live P&L on this page.
Who should skip
Skip this page if you wanted a martingale. Skip it if you need our unpublished practice-log screenshot. Skip it if you need Mac.
FAQ
Is 1.024% small enough that five losses “should not happen”?
No. Rare is not forbidden. A desk that sits every day will see the tail.
Can I raise size after a win streak instead?
Not under this rule. Streaks do not write the next risk. The next invalidation does.
What if my written loss rate is 50%?
Then five losses is 0.5⁵ = 3.125%. Still a product. Still not a size-up cue.
Next step
Download the Windows build. After the next two losses, write the product before you touch size.
Educational content. BarionQuant is not a broker and does not provide investment advice or trade signals. Past practice results do not predict future outcomes. The 40% column is an assumption, not a measured sample from this desk.
