Is there a big-drop trailing buy order type?

Is there a trailing BUY order type that will execute after a certain % or dollar-amount decline in the underlying stock?
At fidelity, i think i can place an order that does this but only on a day to day basis. iow, the change has to occur intraday for the order to go off. iow pt 2: you can put in an order to buy XYZ is it declines by, say, 20% (can anyone say flash crash?) but that decline is based only on yesterday's close.
it does trail in the sense that today's trigger price rises or falls depending on yesterday's close.
but what i want is to be able to place a trailing buy order on a % decline since the order was entered, no matter if that % decline occurs in one day or over two weeks or two months.
possible?

Unless I am not understanding this correctly I believe what you are wanting is just a simple limit order. Let me give a for instance to make sure I am understanding you correctly.

Stock XYX is trading at $100 a share today. You want to buy it if it drops 20% to $80 a share. Doesn't matter if this occurs one day, one week, or one month from now.

If this is correct then you would just set a limit order for however many shares you want at $80 and make it a good until cancelled order. The only thing you may need to do is extend the order every month. I use MerrillEdge and my good until cancelled order expire after a month unless I extend them.

Note that this type of order will execute even if the stock gaps lower, you will just be filled at a lower price (good if buying).

Also note that unless you have margin, the limit order will likely tie up your capital. For me if I place a limit buy order, the money for that order is set aside until the order gets executed. So the money I have available to invest decreases. With margin it still is tied up, but I could effectively place more orders than I have money to cover if I wanted.

Let me see if I can explain it a little better. What I'm after is, say, a purchase after a 20% decline from any high mark after i place my order.

XYZ is trading at $100 a share. If it goes no higher than 100 but instead drops 20%, the order would then execute at $80. that's a limit order, per your example.

***but *** if it first goes to, say, 120, and declines from there, then instead of $80 being the buy point, i want it to be 120 - 20% or $96.

in other words, the buy point trails the rising price by 20% (or whatever) instead of staying at a static amount.

like i said, i'm pretty sure you can do this on an intraday basis. and i also think you can put in buy orders to excute at 52 week lows. but what i'm looking for is slightly different.

have i made myself any clearer? if not, let me know and i'll try again.

That clears it up. I do not have the answer. I will say though that once my account turned into a pattern day trader account I gained access to many more order types than I had initially (including trailing stops...never used them though so I don't know how exactly they work for my account). I think some of these more special type orders may vary by broker, so the best thing to do may just be to call them up and ask.

thanks much, and i will. i was also hoping that somebody here would see what i wrote and say yup, you can do that at my broker. anyone?