What it answers
A prop-firm challenge sells a simple promise: pass the evaluation and trade the firm’s money. The price on the page is one
attempt. What a trader really pays is every attempt until one passes, plus the monthly charges while an attempt drags on,
plus the fee to activate the funded account. And the one number the trader controls, the risk per trade, decides most of it.
This board answers both halves of the question with your own numbers: your win rate, reward-to-risk, trades a day, risk
per trade and costs, against the challenge’s own rules (the profit target, the maximum drawdown and how it trails, the
daily loss limit, the minimum and maximum days) and its prices. It gives the chance that one attempt passes, how attempts
end, how long they take, the expected total cost to get funded with its typical and bad cases, and the risk per trade that
passes most often and the one that costs least.
It is a simulation: 20,000 attempts are traded trade by trade under the rules you set (5,000 on a phone), then chained
into traders who keep buying attempts until one passes. No firm is named here; the three example rule sets are
illustrations, and every number on the board is yours to set.
How to use it
Answer three questions: how often you win, your average win against your average loss (the reward-to-risk) and
your risk per trade in dollars (what a losing trade loses). The line under each says what it means in money. Trades
per day and the costs per trade (commission and slippage, round trip) sit under Fine-tune. Then pick the challenge:
one of three example rule sets, or My own rules, which opens every rule in place: the account size, the profit target,
the maximum drawdown and its type (static, measured from the starting balance; trailing at the end of the day, from the
highest close; trailing intraday, from the highest balance after any trade), whether the trailing floor stops at the
starting balance, the daily loss limit (none, or a loss that ends the day or fails the challenge), the minimum and maximum
trading days, and the price: a one-time fee per attempt or a monthly subscription (charged again every 21 trading days an
attempt runs), the reset fee after a failure (none means buying a new attempt at the full fee), and the activation fee
after passing. The win rate, reward-to-risk and trades a day have the same names as on the
Day-Trading P&L Calculator and Goal or Blow-Up;
the Day-Trading P&L ↗ and Goal or Blow-Up ↗ buttons open them with the same trader, the risk carried as a share of
the account.
The answer comes first: out of 100 simulated traders like you, how many pass on the first try, what most of them pay to
get funded and what one in ten pays, and the 100 drawn as people, coloured by how many tries they needed. When another
risk per trade passes clearly more often, a tip names it, and Show me sets it. Each Try chip applies one change in
one tap and shows its result before you tap it: risking half as much, winning 5 points less often, a static drawdown,
trading like a scalper (20 trades a day), and no edge at all; a tapped chip turns into undo. When your trading has no
edge after costs, a note under the answer says so.
The two pictures:
- Risk less, pass more: the chance one attempt passes at 16 risk sizes from a quarter to four times yours, the sweet spot (the sizes within a point of the best), and your risk as a dot: drag it, tap the plot, or use the arrow keys.
- What you’ll have spent by the time you’re funded: a staircase. Read across from a price to how many of 100 traders like you are funded by then; each step is one more try (on a monthly price, one more month or one more try).
Show all the numbers opens every readout: the expected profit per trade and the breakeven win rate; for one attempt,
the chance it passes (with the simulation’s own uncertainty), how attempts end, and the median trading days to pass and to
fail; for getting funded, the expected number of attempts, the chance of passing within three, and the expected, median
and 90th-percentile total cost; the risk per trade that passes most often and the one that costs least; the numbers behind
the people, the staircase, the tip and the chips; and three more pictures: the expected cost at each risk, how attempts
end, and on which trading days they pass and fail. How this works says what is simulated and how it is checked.
The equations
The board simulates; two small equations sit under it.
How many attempts. If one attempt passes with chance $p$, and attempts are independent, the number of attempts $A$ until
the first pass is geometric: the first pass comes on attempt $k$ when $k-1$ attempts fail and the next one passes. On
average that takes $\tfrac{1}{p}$ attempts, and the chance of passing within three is one minus the chance of failing all three:
What getting funded costs. On the way there are $\tfrac{1}{p} – 1$ failed attempts on average, then one that passes, then the
activation fee $a$. Write $\bar c_{\text{fail}}$ for the average cost of a failed attempt (the reset fee, or the full fee
when there is no reset fee, plus any monthly charges while it ran) and $\bar c_{\text{pass}}$ for the average cost of the
passing one. Because the failed attempts are independent of how many there are, the averages multiply (Wald’s identity):
The board takes $p$ and both averages from its simulated attempts. The spread of the cost (its median and 90th percentile)
comes from chaining the simulated attempts: each simulated trader draws attempts from them until one passes, at most 100.
A check, for the static drawdown. With a static drawdown, no daily limit, no minimum and no maximum, the pass chance has
an exact answer, and the board’s simulation is checked against it. Wins and losses move the balance on a lattice of whole
dollars. Let $K(x,y)$ be the chance that one day of trading takes the balance from $x$ at one close to $y$ at the next (a
balance at or below the floor is out at once), and $v(x)$ the chance of closing at or above the target tomorrow. The chance
$u(x)$ of passing from $x$ is the chance of passing tomorrow plus the chance of passing later from wherever tomorrow leaves
you, one linear system:
At the board’s defaults with a static drawdown this gives a pass chance of 95.4406 % on a lattice of 999 levels; the
simulation’s 20,000 attempts give 95.4600 % ± 0.1472, 0.13 standard errors away.
Worked examples
A careful trader with a real edge. Open the board at these settings:
a USD 50,000 challenge with a USD 3,000 target, a USD 2,000 drawdown trailing at the close and stopping at the starting
balance, a USD 1,000 daily limit that ends the day, five days minimum, a USD 150 fee and a USD 100 reset. The trader wins
50 % of trades at 1.5 to 1, four trades a day, risking USD 100 a trade with USD 5 in costs: USD 20.00 expected per trade
after costs, where 42.0 % would only break even. One attempt passes 97.74 % of the time (± 0.11), in a median of 35
trading days; the expected cost to get funded is USD 152.31, and the median and 90th percentile are both USD 150, one
attempt. The scan agrees: with a one-time price, waiting costs nothing, and the smallest size, USD 63, passes most often
(99.3 %) and costs least.
The same trader on a monthly price changes the answer. Open the board on that price
(USD 49 a month, USD 49 to reset, USD 149 to activate), the same 97.74 % pass chance costs USD 264.62 on average, with a
median of USD 247 and a 90th percentile of USD 345, because the median pass takes 35 trading days, two months of fees.
Here the two best sizes part: USD 63 still passes most often (99.3 %), but USD 276 is the cheapest way to get funded,
USD 213.22 expected. Patience has a price on a subscription.
The same trader risking too much. Open the board at these settings:
back on the first rules, the risk goes to USD 1,000 a trade. Each trade now expects USD 245.00, but two net losses end the
attempt, and every losing trade ends the day at the daily limit. One attempt passes only 46.03 % of the time; 53.97 % end
at the drawdown, in a median of 2 trading days. It takes 2.17 attempts on average, the chance of passing within three is
84.28 %, and the expected cost to get funded rises to USD 267.25 (median USD 250, 90th percentile USD 450). The scan points
back down: USD 250 a trade passes 82.08 % of the time, for USD 171.83 expected.
A trader with no edge. Open the board at these settings:
the first rules again, a 50 % win rate at 1 to 1, USD 200 a trade, USD 5 in costs. Every trade loses USD 5.00 on average
(it takes 51.25 % just to break even), and the board says so under the answer. One attempt passes 17.06 % of the time; it takes 5.86
attempts on average, three attempts pass only 42.9 % of the time, and the expected cost to get funded is USD 636.17 (median
USD 450, 90th percentile USD 1,350). The scan’s best size is its biggest, USD 800 a trade: 27.56 %, USD 412.84 expected.
That is the bold-play result, which the notebook
The Bold Play That Passes the Funded Challenge
works through on real futures data: without an edge, the fewer trades an attempt takes, the better its odds, and passing
becomes a matter of luck, not skill. A pass bought that way does not make the trading profitable.
Assumptions and limits
- Trades are independent, with a fixed win rate and fixed sizes of win and loss. A real edge is uncertain and changes with the market; the board takes yours as known.
- The drawdown is checked after every trade, as firms watch it live; the daily limit counts the day’s closed trades; a trailing floor at the end of the day moves only at the close. Trades are closed one at a time: open-trade swings inside a trade are not modelled.
- The trader keeps trading normally until passing, including after reaching the target before the minimum days are done.
- A day that cannot touch any limit (a floor that cannot move inside it and is out of reach even if every trade loses) is drawn whole, its number of wins from the binomial odds of the day; this gives the same results, faster.
- With no maximum, an attempt stops at 252 trading days and counts as “still going”, and as not passed when attempts are chained. A simulated trader stops after 100 attempts; the board reports how many do.
- When attempts run very long (a tiny risk against a wide drawdown at hundreds of trades a day) the board simulates fewer of them and says how many.
- Rules vary by firm and change. The example rules are illustrations, not any firm’s: check your own firm’s rules and prices. Consistency rules, news-trading bans, contract limits, scaling plans and payout rules after funding are not modelled, and a single evaluation phase is modelled, not two.
- Passing is not getting paid. A funded account has its own rules, and most of the money a trader makes or loses comes after this board stops.