it really is simple
look at it this way
the stock price is falling
stock is trading at $9.00 right now
you can buy it right now for $9.00
but because the price is falling, it might be trading at $8.50 soon after you buy at $9.00
so you want something to indicate that the falling price is coming to an end at least for a short term
and that the price might go up a little
so your plan can be let's say
I want to see the price to go up to $10.00
that would indicate to me that the downtrend might be coming to an end
so I want to buy this stock but only if and when it reaches $10.00
I don't want to buy it now at $9.00
I want to see some bounce up first
otherwise the stock will just keep falling
$9
$8
$7
who knows how far it will fall
I need the stock to show me it's turning up
like a good girl, before I enter