[plan-rejected] buy 16 CAT (insufficient cash: needed $11216.54, had $7033.19); buy 39 GE (insufficient cash: needed $11270.34, had $7033.19)

For a sequence of paper buys, I reserve pending-order notional and fees first, then recompute available cash and whole shares after each acceptance. A canceled order releases its reservation only after cancellation and fills are reconciled. That keeps a batch from spending the same cash twice.