This Boom and Crash lot size calculator works out how many lots to trade for a chosen risk, using the stop distance and the value per point of the instrument you are actually on. It is built for Deriv’s spike indices, where the minimum lot is larger than most traders expect and getting size wrong is expensive.
Value per point and minimum lot come from your own terminal — in MT5, right-click the symbol in Market Watch and choose Specification. They differ by instrument and by regional entity, so read them rather than assuming.
How to use the Boom and Crash lot size calculator
Four numbers decide the answer, and two of them must come from your own terminal rather than from any website:
- Account balance — what you actually have, not what you intend to deposit.
- Risk per trade — the share of the balance you accept losing if the stop is hit. One to two percent is the conventional range, and it exists because a run of losses is normal rather than exceptional.
- Stop loss in points — the distance from entry to stop, in points as MT5 counts them.
- Value per point per lot — what one point of movement is worth on one full lot of that instrument.
Finding value per point and minimum lot in MT5
In MetaTrader 5, right-click the symbol in Market Watch and choose Specification. That panel gives the contract size, the minimum and maximum volume, and the volume step for the exact instrument on the exact account you are trading.
Read it rather than assuming it. Deriv publishes its trading specifications, but the values differ by regional entity and change over time — which is precisely why this tool asks you for the number instead of shipping a built-in table that quietly goes stale.
The minimum lot trap on Boom and Crash
Most traders arrive expecting a 0.01 minimum because that is normal on forex pairs. On Deriv’s published specifications, Boom 500 and Crash 500 have a minimum volume of 0.2 — twenty times larger. Confirm the figure for your own account, because it varies by entity.
The consequence is easy to miss. On a small balance with a wide stop, the size your risk budget actually justifies can be smaller than the smallest trade you are allowed to place. At that point you are not risking one percent; you are risking whatever the minimum lot happens to cost, which may be five or ten times more.
The calculator above says so explicitly instead of quietly rounding you up to the minimum. When your budget will not support the minimum lot, it shows what the minimum would actually cost you, in currency and as a percentage of your balance. Widening the account, tightening the stop, or skipping the trade are the three honest options.
Why this Boom and Crash lot size calculator rounds down
Lot sizes must land on the broker’s volume step. A calculated 0.237 has to become something tradeable, and there are two directions to go.
This tool always rounds down. Rounding up produces a position slightly larger than the risk you specified, which quietly breaks the only rule position sizing exists to enforce. Rounding down risks marginally less than intended. Over hundreds of trades the difference is small; the discipline is not.
The formula behind the Boom and Crash lot size calculator
No mystery in it:
Lots = (Balance × Risk%) ÷ (Stop in points × Value per point per lot)
A worked example. On a 500 balance risking 1%, the budget is 5. With a 200-point stop on an instrument worth 1 per point per lot, one full lot would lose 200 — so the answer is 5 ÷ 200 = 0.025 lots. If that instrument has a 0.2 minimum, the smallest permitted trade would risk 40, or 8% of the account. That is the trap above, in numbers.
Sizing is not a strategy
A Boom and Crash lot size calculator tells you how much, never whether. Position sizing limits the damage of being wrong; it does not make an entry good. Boom and Crash spikes are asymmetric — the risk of holding a short on a Boom index is not the mirror of holding a long — and no sizing formula compensates for ignoring that.
If you intend to automate, the spike-trading robot guide covers which settings actually change outcomes. For the instruments themselves see the Boom 500 index guide, and for where they are listed, our guide to brokers carrying them.
Frequently asked questions
Does it work for Volatility and Step indices too?
Yes. The arithmetic is identical for any instrument — enter that symbol’s value per point and minimum lot from its specification panel.
Why not just fill in the values automatically?
Because they differ by regional entity and change. A built-in table would be right today and wrong later, without ever telling you it had gone wrong.
What risk percentage should I use?
That is a personal decision, not a formula. One to two percent is conventional. The relevant question is how many consecutive losses your account and your temperament can absorb.
Is a smaller stop better because it allows a bigger position?
No — that reasoning is backwards and expensive. The stop belongs where the trade is invalidated. Moving it closer to justify size just means being stopped out more often.
Trading leveraged products carries significant risk and can result in the loss of your capital. Nothing on this page is investment advice.