Splitting One Risk Budget Across Three Trades

[Fairman]

Splitting One Risk Budget Across Three Trades

Scenario: you like a dollar-weakness idea and want to express it through EUR/USD, GBP/USD, and AUD/USD. Your account is 12,000 dollars, and your rule says a single idea may risk at most 1 percent in total.

Work it out. Total risk budget: 120 dollars. Since the three trades share one theme, the risk is concentrated. If the dollar rallies, all three stops are likely to be hit together. So divide the budget: 40 dollars per trade.

Now size each. EUR/USD with a 20-pip stop: per standard lot, 200 dollars, so 40 divided by 200 is 0.20 lots. GBP/USD with a 30-pip stop: per lot 300 dollars, so 0.13 lots. AUD/USD with a 25-pip stop: per lot 250 dollars, so 0.16 lots.

Total risk if all three stop out: roughly 40 plus 39 plus 40, about 119 dollars, which is 0.99 percent. The plan holds.

Compare with the common error. A trader who risks 1 percent on each of the three, believing they are independent, risks 3 percent on one idea. If the idea fails, the loss is three times what the rule intended.

Takeaway: when positions share a currency, treat them as one position for risk, and divide the budget.

Practical step: take any three open or planned trades and group them by shared currency, then compute the combined risk per group.

[FXS HongKong Scalper]

Splitting the budget is the right default. One adjustment we use: weight by how strongly the pairs move together rather than splitting equally. EURUSD and GBPUSD are often 0.7 or more correlated on daily returns, AUDUSD somewhat less, so in practice the three positions behave like about two independent ones.

Also check the rounding. 40 divided by 300 is 0.133, so 0.13 lots gives 39 dollars of risk, fine. But if the AUDUSD stop were 15 pips, the result would be 0.266 and rounding up to 0.27 would put you over the budget. Always round down when the total is capped.

[Fairman]

The sizing checks out. EUR/USD at 0.20 lots with a 20 pip stop risks 40 dollars. GBP/USD at 0.13 lots with 30 pips risks 39. AUD/USD at 0.16 lots with 25 pips risks 40. The total of 119 dollars stays within the 120 dollar budget. Rounding down on GBP/USD, from 0.133 to 0.13, kept the total just under. That's the right way to handle it: calculate each trade's share, round each one down, and confirm the total. If rounding pushed any trade over its share, the total would exceed the budget, and the rule would be quietly broken.

[Amanhasnoname]

I learned the shared-currency lesson on a day when I was long EURUSD, GBPUSD and short USDCHF, all on the same weak-dollar idea. I had sized each at a normal risk and told myself they were three trades. A hawkish speaker hit during the New York session and all three stops went within about eleven minutes, which cost me close to three times what I had planned for one idea.

Since then I count exposure per currency instead of per ticket. I keep a tiny sheet with one row for each currency and add up how many pips of stop I am carrying long or short in it. If the dollar row shows more than my single idea budget, I cut size on the weakest setup before I place anything else.

One more practical point is to put the least liquid pair at the smallest share, because AUDUSD tends to slip more at stop out than the majors do. I usually give the cleanest chart about half of the budget and split the rest between the other two.

[Fairman]

Dividing the budget equally is a simple starting point, but there are alternatives. Some traders weight the split by conviction, putting more of the budget on the pair with the clearest setup. Others weight by expected reward, giving more to the pair with the best ratio. Still others choose just one pair to express the idea, on the logic that if all three are likely to move together, there's little benefit in spreading across them. Each approach respects the total budget. The important thing is that the total for the idea stays at 1 percent, whichever split is chosen.

[Fairman]

It's worth noting that the three pairs don't move perfectly together. On some days, the dollar might weaken broadly but the pound might fall on UK news, or the Australian dollar on Chinese data. So spreading across three pairs gives some diversification against non dollar risks, even though the dollar exposure is shared. That's a reasonable argument for using several pairs, as long as the total dollar risk is capped. The worst case, all three stopping out together, is still the scenario to size for, since it's the most likely way the idea fails.

[Fairman]

Grouping open trades by shared currency, as the practical step suggests, often reveals hidden concentration. A trader might think they have five independent trades, only to find that four of them are effectively short the dollar. Building a small table with the currencies as columns and each trade's risk as plus or minus under the relevant currencies makes this visible in seconds. Has anyone here set a rule for maximum risk per currency or per idea? I'd be interested in what level people chose and how often it stopped them from adding another correlated trade.