How to pick a challenge size

Most challenge rules are percentages of the starting size. An 8% target and an 8% max loss ask the same of you on $5,000 as on $200,000. What changes is the dollar amount behind each percent.

That has three effects:

• The reward. A 5% profit at an 80% split is $200 on $5,000 and $8,000 on $200,000.
• The swings. A 1% loss is $50 on $5,000 and $2,000 on $200,000. Same percent, very different feeling.
• The price. A bigger size usually costs more, because the rewards it can pay are bigger.

Here is one set of rules at every size Runtiler offers: an 8% max loss, 1% risked per trade, and a 5% profit claimed at an 80% split.

Every row is the same challenge in percent. Only the zeros move.

The price is what you can lose for real. The account balance is simulated, so the most a challenge can cost you is what you paid for it.

A useful way to compare sizes is to ask what each try costs and what it can pay. Here is a sum with made-up prices, only to show the method (every challenge shows its own price):

• Say a $10K challenge costs $60 and a $100K one with the same rules costs $400.
• At 5% profit and an 80% split, the $10K pays $400 and the $100K pays $4,000.
• For the $400 of one $100K try, you could buy six $10K tries ($360).

Neither choice is right for everyone. The bigger account pays more per success. The smaller ones give you more attempts for the same money while you are still learning the rules. Run this sum with the real prices before you buy.

Traders often pick the largest size they can afford because the reward looks better. A few things work against that:

• Dollar swings change behaviour. If a $2,000 loss on a normal day makes you want to win it back at once, the size is too big for you right now, whatever the percent says.
• One try costs more. A larger price means a failed attempt hurts more, and you may get fewer attempts in total.
• The rules don't get easier. The target, the max loss and the daily limit are the same percentages. A bigger size doesn't give you more room in percent.

A good habit is to pick the size where a full losing day at your normal risk is an amount you can look at calmly.

Your style matters too, because trade sizes come in steps and margin has limits.

Small accounts and wide stops

Every market has a smallest size. On gold it is 0.01 lot, which is 1 ounce. Say you trade gold on a $5,000 account and risk 1%, which is $50:

• With a $15 stop, 0.01 lot risks $15, so 0.03 lot risks $45. That fits.
• With a $60 stop, even 0.01 lot risks $60, which is 1.2%. You can't go smaller.

If you use wide stops, a small account can force you to risk more than you planned. A bigger size gives you finer steps.

Margin and leverage

Leverage on Runtiler is set per market, not per challenge, so it is the same at every size. What changes is how much you can hold. At 1:5 on Bitcoin, a $5,000 account can hold about $25,000 of Bitcoin (0.25 BTC at $100,000) before margin runs out. A $50,000 account can hold ten times that.

If you size your trades by risk with tight stops, a small account can reach its margin limit before it reaches your risk limit. See Leverage and margin for how margin and stop-out work.

Short, frequent trades

Spreads, commissions and overnight fees are percentages of each trade's value, so they cost the same share of the account at every size. Frequent traders don't gain or lose from size on costs. They do feel the swings more on a big account, because there are more of them.

1. Decide what you risk per trade in percent. Many traders use 0.5% to 1%.
2. Look at your usual stop distance and check that the smallest trade size at each account size is at or under that risk.
3. Work out a bad day: three or four full losses at that risk. Pick a size where that dollar amount doesn't change how you trade.
4. Compare the price to what you are willing to spend on attempts, not only on one.
5. Prefer the smaller of two sizes that both pass these checks while you are new to the rules.

Runtiler challenges come in six sizes: $5K, $10K, $25K, $50K, $100K and $200K. Each challenge is made by a creator and has its own price, set from its rules, and the size is one of those rules.

Every step, and every claim, starts the account again at its full size, so the dollar amounts in the table stay the same all the way through. If you change your mind after buying, you can get the price back until your first trade on that account: see Refunds.

For what to risk on each trade once you've picked a size, read Risk per trade and Position sizing.