Hi Lou, Re: Entering potential trades based on AIM signals............
I have used "GTC" Limit orders on my transactions for decades. Generally if the markets are in a rising time I have open orders on most of my positions to Sell. Since there's such a large discount from a sell to a buy, I don't usually have open orders on the buy side simultaneously.
The same is true during market declines but reversed. I load up the broker's order sheet with buys, but usually don't have many open sells at that time.
If you are buying and selling ETFs that have healthy dividends and your brokerage of choice lets you, make your open Limit orders GTC and add a "do not reduce" qualification as well. That keeps the limit price what you want it to be. Otherwise the brokerages tend to reduce your limit price by the amount of any dividends paid since the order was entered.