How to size a crypto position so you don't blow up

Most accounts don't die from bad calls. They die from one oversized trade. Here's the sizing method that keeps you in the game — in plain English, with the exact math.

You can be right more often than wrong and still go broke. All it takes is one position big enough that a normal move wipes out months of progress. That's not bad luck — it's bad sizing. The single highest-leverage skill in trading isn't picking winners; it's deciding how much to put on each one.

The one rule: risk a fixed, small slice per trade

Before you think about entries, decide the only number that actually protects you: the most you're willing to lose on a single trade. Pros keep this small and constant — usually 0.5%–2% of the account per trade. Let's use 1%.

At 1% risk, you could be wrong ten times in a row and still only be down ~10%. That's a bad week, not a blown account. The whole point is to make any single loss survivable, so you're still standing when your edge plays out.

Size is an output, not a guess

Here's the part most people get backwards. You don't pick a position size because it "feels right." You derive it from two things you already know: how much you'll risk, and where your stop is.

Worked example. Say you have a $10,000 account and risk 1% ($100) per trade. You want to buy a coin at $100, with a stop at $90 — a 10% distance to your stop.

So you buy $1,000 worth — not because $1,000 felt right, but because that's the size where hitting your stop costs exactly your 1% ($100). Tight stop → bigger position. Wide stop → smaller position. The risk stays fixed; the size adjusts. That's the whole trick.

Why "quarter-Kelly," not full Kelly

The Kelly criterion is the math for the theoretically optimal bet size given your edge. The problem: it assumes you know your edge precisely, and it's brutally aggressive. In crypto — fat tails, fake-outs, exchanges that wick your stop — full Kelly will over-bet and eventually ruin you.

The fix the pros use is a fraction of Kelly. Quarter-Kelly (25%) keeps most of the growth while slashing the swings and the risk of ruin. When you don't truly know your edge — and in crypto, you don't — betting a fraction of "optimal" is the honest, survivable choice.

The three mistakes that actually blow accounts

• Sizing by conviction. "I'm really sure about this one" is how the biggest losses get made. Conviction is not a position-sizing input — your stop is.
• No stop, or a mental one. If you can't define where you're wrong before you enter, you can't size the trade — and you'll hold a loser all the way down.
• Stacking leverage on top of size. Leverage multiplies the distance-to-stop math against you. A 10x position needs only a ~10% move to liquidate. Size first, then ask if leverage is even necessary (it usually isn't).

How Quant Terminal does this for you

This is the math our Risk Engine runs automatically. Punch in your equity and a stop, and it returns a quarter-Kelly size and a hard invalidation level — the same discipline above, without the spreadsheet. And our Trade Check grades a trade before you take it, flagging the oversized, no-stop, over-levered setups that blow accounts. The goal isn't to promise you profits — it's to stop you from blowing up.

Quant Terminal is research and educational software — not financial advice, and not a recommendation to buy or sell anything. Crypto is extremely volatile and you can lose your entire investment. Position sizing reduces risk; it does not eliminate it. Always do your own research.