position sizing, fixed lot vs percentage of equity

[william_h]

classic debate. two main approaches:

1. fixed lot size per trade (always trade X lots regardless of account size)
2. percentage risk per trade (risk Y% of current equity per trade)

arguments for fixed: simpler, more predictable income from each trade, easier to size strategies that need specific dollar exposure
arguments for percentage: compounds on wins, reduces during drawdowns, adapts to account growth

whats your approach and why?

[darkhorizon]

percentage based, 0.5-1% risk per trade. the compounding upside on winning periods + automatic risk reduction during losing periods is mathematically optimal long-term. fixed lot has psychological appeal (more predictable) but mathematically inferior for account growth.

[wildnorth]

started percentage based, switched to fixed lot for prop firm accounts where account size doesnt really 'grow' since you withdraw. for own capital accounts percentage compounds nicely. for prop accounts fixed lot makes more sense. use case matters.

[endlessroad]

+1 on the use case distinction. percentage for compounding capital, fixed for withdrawal-heavy accounts (props, accounts where you take income regularly). not 'one is right' - 'depends on goal'.

[mellowday]

how do i calculate percentage risk in lots? i find this confusing

[Jake]

formula: position size = (account x risk%) / (stop loss in pips x pip value). example: $10,000 account, 1% risk = $100. stop loss 50 pips, pip value on 1 standard lot EURUSD = $10. so position size = $100 / (50 x $10) = 0.2 lots. most platforms have a position size calculator built in or available as free indicator. use it.

[zacharyy]

the position sizing debate is meaningless. youre going to blow it up either way if your edge is wrong. solve the edge problem first then worry about whether to risk 0.5 or 1%.

[dreamchaser]

position sizing matters massively. two traders with the same 55% win rate strategy will end up with very different equity curves depending on whether they risk 0.5% or 3% per trade. risk management is half the equation. dont dismiss it as 'just solve the edge problem'.

[parkerlee]

going from 'i feel like trading 0.5 lots today' to systematic percentage sizing was my biggest single improvement not because the math was better (it was) but because i stopped deciding sizing emotionally. discipline removes the bad decision

[Nicholas]

percentage. compounds.