Position sizing in crypto: deciding how much to put at risk
Position sizing answers one question before every purchase: how much can this lose without hurting me? Diversification and rebalancing keep the answer true over time. Here is the arithmetic, with worked examples.
Photo: “Egg Basket, Ethiopia” by Rod Waddington, CC BY-SA 2.0, via Flickr (edited: cropped and resized).
Position sizing means choosing how much to put into one holding based on the most you accept losing. Units = (account × risk %) ÷ (entry − exit price). If the realistic worst case is zero, the position should not exceed money you can afford to lose entirely [1].
Key points
- 1Decide the loss you accept first; the position size follows from it and from how far the price could fall.
- 2The further the price could realistically fall, the smaller the position. If it could fall to zero, size equals your maximum loss.
- 3Exit orders can fill below the planned price in fast or thin markets, so build in a margin of safety.
- 4Diversification spreads money across investments that may behave differently; owning many similar coins may not do that.
- 5Rebalancing brings a holding that has grown back to its planned share, before a fall makes it hurt more.
On this page
- What is position sizing?
- How do you calculate a position size?
- What if the price could fall to zero?
- Why can losses exceed the plan?
- What does diversification actually do?
- Does owning many cryptocurrencies diversify you?
- How does rebalancing keep your sizes in check?
- What mistakes do beginners make here?
- Frequently asked questions
- The bottom line
- Sources
What is position sizing?#
A position is the amount you hold of one asset. Position sizing is deciding how big that amount should be. Most beginners do it backwards: they pick a coin, decide how much they would like to buy, and only later think about what could be lost. Position sizing flips the order. You start with the loss you are prepared to accept and work out the purchase from there.
That starting number is personal. The SEC defines risk tolerance as your ability and willingness to lose some or all of an investment in exchange for greater potential returns [2], and its crypto alert sets a hard outer limit: the only money you should put at risk in any speculative investment is money you can afford to lose entirely [1].
How do you calculate a position size?#
Units = (Account × Risk %) ÷ (Entry price − Exit price) · Position value = Units × Entry priceAccount × Risk % is the money you accept losing. Entry − Exit is what you lose per unit if the price reaches the level where you plan to sell. The result is the number of units at which hitting the exit costs exactly the money at risk.
| Step | Value |
|---|---|
| Money at risk = $10,000 × 1% | $100 |
| Loss per unit at the exit = $100 − $90 | $10 |
| Units = $100 ÷ $10 | 10 |
| Position value = 10 × $100 | $1,000 (10% of the account) |
| Loss if the exit is hit = 10 × $10 | $100 (1% of the account) |
The position size calculator runs the same arithmetic for any numbers you enter.
The distance to your exit drives everything. For a fixed risk, the maximum position shrinks as the possible fall grows:
| Fall to your exit | Max position at 1% risk | Max position at 2% risk |
|---|---|---|
| 5% | 20% of account | 40% of account |
| 10% | 10% of account | 20% of account |
| 20% | 5% of account | 10% of account |
| 50% | 2% of account | 4% of account |
| 100% (goes to zero) | 1% of account | 2% of account |
Computed as risk ÷ fall. Ignores fees and slippage, which make real losses larger.
What if the price could fall to zero?#
For many crypto-assets, zero is not a theoretical case. EU regulators warn that you may lose all the money you invest [3], and the SEC notes that the market for a particular crypto asset may disappear altogether [1]. If you hold without an exit price — as most long-term holders do — the honest assumption is a 100% fall, and the last row of the table applies: the position should be no larger than the amount you are prepared to lose in full.
Why can losses exceed the plan?#
The exit price is a plan, not a promise. A stop order — the CFTC notes it is sometimes called a stop-loss order [4] — becomes a market order once the stop price is reached, and the SEC warns the price you actually get may differ from the stop price, especially in a fast-moving market [5]. A short-term dip can also trigger the stop before the price recovers [5]. In thin markets you may not find a buyer at a fair price at all [3].
In the example above, if the price gaps from $91 to $85 and your order fills at $85, the loss is 10 × $15 = $150, or 1.5% of the account instead of 1%. Leaving room for that — by risking a little less than your true limit — is part of sizing. Borrowing makes the gap far more dangerous; see leverage.
What does diversification actually do?#
The SEC sums up diversification as “don’t put all your eggs in one basket”: spreading money among various investments in the hope that, if one loses money, gains in the others offset those losses [6]. Its beginners’ guide explains the logic with a street vendor who sells both umbrellas and sunglasses — rain helps one product and hurts the other, so the vendor is less likely to have a terrible day [7].
The key, according to the same guide, is to hold investments that may perform differently under different market conditions, and to diversify at two levels: between asset categories such as stocks, bonds and cash, and within each category [7]. Position sizing limits the damage from any single holding; diversification aims to stop all your holdings from being hit at once.
Two tools, two different jobs
Does owning many cryptocurrencies diversify you?#
Not necessarily. Ten coins are only diversified if they tend to behave differently. Many risks regulators list apply across crypto as a whole — extreme price movements, platform failures, hacks, the absence of deposit-style protection [3] — so a portfolio of ten coins on one exchange can share a single weak point. The market is also concentrated: in 2022 the ESAs noted that bitcoin and ether together made up about 60% of total crypto-asset market capitalisation [3].
More holdings also mean more fees, which lower returns, and more things to track [7]. Before adding a coin “for diversification”, ask what it would do differently in a market-wide fall. If you cannot answer, it is probably adding risk rather than spreading it. Our guide on how to evaluate a crypto project helps with that question.
How does rebalancing keep your sizes in check?#
A position that grows quickly becomes a bigger share of your money than you planned. Rebalancing brings a portfolio back to its original mix [8]. The SEC’s guide describes three ways to do it: sell some of what is over-weighted, buy more of what is under-weighted, or direct new contributions to the under-weighted part until the mix is back in line [7].
| Step | Value |
|---|---|
| Start: other assets / crypto | $9,000 / $1,000 |
| After crypto +100%: total | $11,000 |
| Crypto share now = $2,000 ÷ $11,000 | 18.2% |
| 10% target = $11,000 × 10% | $1,100 |
| Sell to rebalance = $2,000 − $1,100 | $900 |
| If crypto then falls 50%, without rebalancing: total | $10,000 |
| If crypto then falls 50%, after rebalancing: total | $10,450 |
Rebalancing does not always come out ahead — if crypto had kept rising, holding more would have ended higher. What it does is keep the position at the size you decided you could afford to lose. Check fees and tax consequences before selling [7].
- Set your maximum loss
For the whole crypto portion and for each holding, in dollars.
- Choose an exit or assume zero
Either a price where you will sell, or the assumption that the holding could be worthless.
- Size each position
Risk ÷ fall to exit. Leave room for slippage.
- Check what you really own
Count how many holdings share the same platform, network or theme.
- Rebalance on a schedule or a threshold
The SEC’s guide mentions every six or twelve months, or when a weight drifts past a limit you set in advance.
What mistakes do beginners make here?#
- Sizing by conviction
Feeling sure about a coin is not a reason for a bigger position. The loss you can afford does not change with how confident you feel.
- Ignoring the fall to zero
Many crypto-assets can lose all their value. A position sized for a 20% fall is five times too large if the real risk is 100%.
- Treating the stop price as fixed
Stops become market orders and can fill well below the stop in a fast market.
- Calling ten similar coins “diversified”
If they share the same platform, network or market mood, they may fall together.
- Letting winners grow unchecked
A position that has tripled is now three times the size you planned. Rebalancing restores the plan.
Frequently asked questions#
What percentage of my account should I risk per trade?
There is no universal number; it depends on your risk tolerance and finances. The method works with whatever percentage you choose, and smaller is more forgiving while you learn.
Is position sizing only for traders?
No. Long-term holders need it too — they simply use a 100% fall as the exit, which makes the position equal to the most they can afford to lose.
How many coins do I need to be diversified?
Count matters less than difference. The SEC’s guidance is about holding investments that may perform differently under different market conditions, across and within asset categories [7].
How often should I rebalance?
The SEC’s guide describes two approaches: on a calendar, such as every six or twelve months, or when a holding drifts past a threshold you set in advance; it adds that rebalancing tends to work best when done relatively infrequently [7].
Does diversification remove risk?
No. It aims to reduce the chance of everything falling at once, and it can lower volatility, but all investments carry risk.
The bottom line#
Position sizing is the habit that keeps a bad call from becoming a disaster: decide the loss first, measure how far the price could fall, and let the arithmetic set the size. Diversification and rebalancing keep those sizes honest as markets move.
Next, see why deep falls are so hard to recover from in drawdowns and recovery math, or try the numbers yourself with the position size calculator.
Sources#
Grade A = primary source (regulator, protocol specification, client code, original author). Grade B = expert secondary source used for explanation only.
- AU.S. SEC, Investor.gov. Exercise Caution with Crypto Asset Securities: Investor Alert, 2023.
- AU.S. SEC, Investor.gov. Risk Tolerance, 2026.
- AEuropean Supervisory Authorities (EBA, ESMA, EIOPA). EU financial regulators warn consumers on the risks of crypto-assets, 2022.
- AU.S. Commodity Futures Trading Commission. Futures Glossary: A Guide to the Language of the Futures Industry, 2026.
- AU.S. SEC, Investor.gov. Stop Order, 2026.
- AU.S. SEC, Investor.gov. Diversification, 2026.
- AU.S. SEC, Investor.gov. Beginners’ Guide to Asset Allocation, Diversification, and Rebalancing, 2026.
- AU.S. SEC, Investor.gov. Rebalancing, 2026.
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