Fixed lot, fixed fractional, or volatility — pick your sizing style

Ask ten traders how they size a position and nine will say "a standard lot" or "whatever feels right." Sizing style is the decision that silently runs the account — and most traders never actually made it. There are three honest options, and the differences between them are not subtle.

Style 1: fixed lot — the accidental system

You trade one lot, or 0.1, every time, regardless of stop distance or account size. It feels disciplined because it is consistent — but the risk per trade swings wildly. A 20-pip stop risks a fifth of what a 100-pip stop risks on the same lot. Two "identical" trades can differ five times in damage. Fixed lot is fine only when your stops are always the same distance — which they never are.

Style 2: fixed fractional — the professional default

You pick a risk percentage (say 1%), convert it to cash ($1,000 on a $100,000 account), and divide by the stop's pip cost to get the lot size. Every trade risks the same slice of the account, whatever the stop distance. This is what the position size calculator does for you. The property that matters: a losing streak shrinks your size automatically, a winning streak grows it. The math leans in your direction when you compound — and against you when you don't.

Style 3: volatility targeting — the advanced move

You size not just by stop distance, but by how much the market moves. If the pair's daily range doubles, your size halves — the trade's dollar wobble stays constant. It's the difference between risking 1% on a calm instrument and 1% on a wild one; both can hit the same stop percentage, but the wild one gets stopped out more often. Volatility targeting smooths the ride, at the cost of more math and more rules. A workable middle ground: fixed fractional with a volatility filter — skip the trade entirely when the stop is tighter than the pair's typical noise.

Why switching styles is the real danger

The costly pattern is not picking the wrong style — it is rotating through all three mid-drawdown. Fixed fractional after a loss, fixed lot after a win, "small size, it's safer" on the trade you're unsure about — that is not risk management, that is mood management. Pick one style, write it down with its percentage, and test it for a month before you change a single parameter. The pip-value table tells you what each pip costs; the sizing style tells you how many of those pips you are allowed to lose.

The one number that ties it together

Whatever the style, convert it to one figure: cash risked per trade as a percent of the account. If you can't name that number in one sentence, you don't have a system — you have a habit. Name it, keep it boring (most professionals live between 0.5% and 2%), and let the style handle the rest. One rule, same every day, is worth more than the perfect style applied differently every week.