Not having a bankroll at all

Without a defined pot, stake size is set by whatever happens to be in the account, which means by how the last week went rather than by any decision.

A bankroll is not primarily a discipline exercise. It is the denominator that makes every later measurement mean something — units, return, drawdown and risk of ruin are all undefined without it.

The amount matters far less than the fact of it being fixed. A small bankroll consistently applied produces a readable record; a large one applied by mood does not.

Which is where it goes wrong. Not having one feels like flexibility. It is the absence of a denominator, and everything downstream inherits the problem.

What to do with it. Set aside an amount you can lose entirely, keep it in a separate account, and define a unit as a fixed percentage of it.