It's not just you mate, I can't work it out either.... I rang them once to try to confirm it and it was just more confusing.
In your screenshot it says "at market" so you would assume that means "just sell the damn thing" but it doesn't. It means whatever the last price is, sell three ticks below that, so PEN would be if price reaches .024 then it would place a sell order at .021 which means if there are enough buyers at .024 it will be .024, else .023, else .022 or .021. If the price jumps straight below .021 then your order doesn't get placed (good because if it did get placed at .021 but price had jumped to .018, then started to rally again you'd be selling in an uptrend!)
Makes more sense to me now that the "limit" function might actually mean that you want to sell it if it hits .024 but only at a minimum of .023 for example not .022 or .021. So you are telling it to sell one tick or two ticks below rather than the full three ticks????
I was told that this is the way all brokers do it but I'm not so sure.
DISCLAIMER: Do not do this next thing without checking with eTrade first!.... Only other possibility in my head is to find one that says "if .024 sell at .01" that way the order definitely gets placed and you get whatever the best price is - if the share is diving do you want out at any price of prefer to sit tight and wait.
