Imagine you have purchased a stock at precisely the wrong moment. The instant you have purchased shares, it begins to drop. It seems like there can be strategies for exiting the position without taking losses if you act in a timely manor. What are the names of the strategies traders use and how do they work?
If the stock is below its purchase price, there is no way to exit the position immediately without taking losses. Since presumably you had Good Reasons for buying that stock that haven't changed overnight, what you should probably do is just hold it and wait for the stock to come back up. Otherwise you're putting yourself into an ongoing pattern of "buy high, sell low", which is precisely what you don't want to do.
If you actually agree with the market that you made a mistake and believe that the stock will not recover any part of the loss quickly (and indeed will continue going down), you could sell immediately and take your losses rather than waiting and possibly taking more losses. Of course if the stock DOES recover you've made the wrong bet.
There are conditions under which the pros will use futures to buffer a swing. But that's essentially a side bet, and what it saves you has to be balanced against what it costs you and how certain you are that you NOW can predict the stock's motion.
This whole thing is one of many reasons individuals are encouraged to work with index funds, and to buy-and-hold, rather than playing with individual stocks. It is essentially impossible to reliably "time the market", so all you can do is research a stock to death before making a bet on it. Much easier, and safer, to have your money riding on the market as a whole so the behavior of any one stock doesn't throw you into a panic.
If you can't deal with the fact that stocks go down as well as up, you probably shouldn't be in the market.