Position arithmetic on a fractional asset

Equities reached the one-unit case; crypto removes the unit entirely. Coins divide to eight decimal places or more, so the sizing division has no remainder - and the arithmetic could not be simpler, which is exactly the trap.

The arithmetic, floorless

Coins times price is the position: £20,000 into a £40,000 coin buys 0.5 coins, and a £400 move on that position is £200 - plain multiplication, plain division, no rounding step because none is needed. The risk-based size from the platform's standard division comes out to whatever decimal it comes out to, and the account holds exactly that. The whole-contract chunkiness of futures and the whole-unit floor of shares are both simply gone.

Why the simplicity is dangerous here

• No friction forces the calculation: no spec to read, no contract to size, no floor to notice - nothing about the trade makes a trader compute the notional, so the habit lapses exactly where volatility punishes the lapse hardest.
• The volatility is the highest on the platform: a coin moving 20% in a session - module 4's opening fact - turns an unsized position into a portfolio event; the notional the trader never computed is the loss they never bounded.
• The denominations confuse the base: a position sized in stablecoins, valued in fiat, against a coin - three units in one trade; the arithmetic is trivial only once the base currency is fixed, per lesson 6.

The self-imposed habit

The tool below sizes crypto positions from account risk and the stop; use it until coins-times-price and risk-over-stop-distance are reflexes. The platform's sizing discipline has been self-imposed since the equity track - nothing forces it - but crypto raises the stakes: the easiest arithmetic on the platform guards the most violent asset on it, and module 4 builds every risk lesson on the number this one computes. The volatility that makes crypto attractive is exactly what makes the unsized position ruinous.