blew up my second account before i figured out something embarrassingly obvious about position sizing

ok bear with me because this is kind of embarrassing

i was sizing by shares for like two years. just... pick a round number. 100 shares, 200 shares, whatever felt right. and i never really thought about it that hard because the math seemed fine

except it wasn't fine at all

the thing i wasn't accounting for is that my stop distance was different every trade. sometimes i'd have a tight stop, like $0.30 away. sometimes it was $1.50 or $2 away because the setup needed room. but i was buying the same number of shares either way

which means on the wide-stop trades i was accidentally risking 4-5x more dollars than i thought i was. i just wasn't thinking about it in dollar terms at all

lost like 60% of my second account doing this. not one blow-up trade, just... a lot of trades where i was overrisking and didn't realize it

the fix is so simple it's annoying. decide how many dollars you're willing to lose per trade. then divide by your stop distance to get share count. so if i'm risking $75 and my stop is $0.50 away i buy 150 shares. if the stop is $1.50 away i buy 50. the dollar risk stays the same, the share count changes around it

that's literally it. i know. i know.

the other thing that helped was a hard daily loss limit where i just stop trading for the day if i hit it. i used to think that was a mental weakness thing. turns out i was just making it way worse every time i tried to "get it back"

anyway. what does your per-trade risk look like, flat dollar or percentage of account? genuinely curious if one works better psychologically