Position Sizing Basics: How Much to Put Into One Holding
By moonbag.info team · · Beginner
Most people spend hours deciding what to buy and seconds deciding how much. In practice, position sizing often matters more. A good idea in a position that is too large can still do serious damage to your finances, and a poor idea in a small position is a lesson rather than a disaster.
This guide explains what position sizing is, a few common frameworks and how to set limits you can actually follow. It does not tell you what to buy, and every number below is illustrative.
What position sizing means
Position sizing is the share of your total investable money that you put into one holding. If you have $10,000 set aside for investing and put $500 into “Token A,” your Token A position is 5% of that portfolio.
Two ideas sit underneath it:
- Crypto assets can fall a lot. Drops of 50% to 80% have happened many times across the market, and some tokens go to zero.
- Losses are harder to recover than they look. A 50% loss needs a 100% gain just to get back to even. An 80% loss needs a 400% gain.
Sizing is how you decide in advance how much of that downside you are willing to live with.
Start with money you can afford to lose
Before any percentage, decide what money is in scope at all. Many people only use money that is left over after:
- An emergency fund (often described as several months of essential expenses).
- High-interest debt is paid down.
- Regular contributions to retirement accounts, if that applies to them.
Money you need for rent, bills or a near-term purchase is usually not a good fit for volatile assets. If losing it would change how you live, it probably is not “risk money.”
Three simple sizing frameworks
1. Fixed percentage cap
Pick a maximum share of your portfolio for any single holding. For example:
| Holding type (illustrative) | Max share of portfolio |
|---|---|
| Larger, longer-established assets | up to 20% |
| Smaller or newer tokens | up to 5% |
| Highly speculative experiments | up to 1% |
The exact numbers are personal. The point is to have a number before you buy.
2. Loss-based sizing
Ask: “If this goes to zero, how much of my total portfolio am I willing to lose?” If the answer is 2% of a $10,000 portfolio, the most you would put in is $200. This works well for speculative positions where a total loss is realistic.
3. Tiered or “core and satellite”
Some people split a portfolio into a larger core of holdings they plan to keep long term and a smaller satellite portion for experiments. For example, 80% core and 20% satellite, with each satellite position capped at a small slice. This keeps curiosity from taking over the whole plan.
A worked example
Imagine a $5,000 crypto portfolio and these personal rules:
- No single holding above 25% ($1,250).
- Speculative tokens capped at 3% each ($150).
- At least 10% kept in cash or a stablecoin for flexibility.
If Token B is a small, new project, the plan caps it at $150 no matter how exciting the story sounds. If Token B then triples, it is now worth $450, which may be 8% or more of the portfolio. That is the moment a rebalancing rule or a profit-taking ladder comes in, which is often how a moonbag is born.
How to write your own sizing rules
- Define your total. Write the dollar amount you consider your crypto portfolio.
- Set a single-holding cap. One number, as a percentage.
- Set a speculative cap. A smaller number for newer or riskier tokens.
- Decide what happens when a position grows past its cap. Trim it, hold it, or set a band (for example, trim only above 1.5x the cap).
- Decide what happens when it shrinks. Will you add more, or leave it? Adding to falling positions without a plan is how small positions become large losses.
- Write it down and keep it where you will see it before every trade.
Position sizing and fees
Very small positions can be eaten by fees. If a gas fee or trading fee is $5 and your position is $50, you lose 10% just getting in and out. Check the full cost of buying, moving and eventually selling before you decide a tiny position is worth it.
Common mistakes
- Sizing by excitement. Putting the most money into whatever feels most exciting this week, often at the peak of FOMO.
- Averaging down without limits. Buying more every time the price drops, until a “small” position is the biggest one you own.
- Forgetting that winners grow. A position that starts at 5% can become 30% after a big run. Not resizing means your risk has quietly grown.
- Counting the whole portfolio as risk money. Including emergency savings in the total makes every percentage look smaller than it really is.
- Ignoring correlation. Many crypto assets tend to move together in big market drops. Ten different tokens are not always ten independent bets.
- No written rule. A rule that lives only in your head tends to change when prices move.
Key takeaways
- Decide the size before you decide the entry.
- Use caps: one for any single holding, a smaller one for speculative bets.
- Revisit sizes when prices move a lot, in either direction.
- Keep fees in mind for small positions.
Position sizing will not make a bad idea good, but it can keep any single idea from deciding your financial future.