"Secure a profit"
If we think to get an edge at a given game and conditions are favourable, we should stay and play regardless of the actual economical situation.
As Albalaha sayed, it's only the long run which counts and itlr everything will come out, thus to secure a profit means "I know I'll surely lose, better to get the illusion to be ahead of something now".
Instead a proper formulation should be: favourable conditions are met, the more I play the more I'll win. Period.
"Quit when you are ahead"
Same bigornsh.it as above.
Our play cannot be splitted into sessions, it's just an infinite series of bets where the cumulative number of times we are ahead (by a W/L ratio) is equal to the cumulative number of times we are behind, all aggravated by the fact that bets are unfair payed in a way or another.
In some sense and oppositely thinking, the specular statement should be "do not quit when behind", a statement particularly liked by casinos.
"Stop win" and "Stop loss"
It depends about what we are considering.
Each class of Ws and Ls follow a general probability and an actual probability. For example I've presented random walks having a general probability to produce all wins for the entire lenght of the shoe, hence lowering the value of a stop win strategy.
On the other hand, some shoes will form many back to back losses that make a future winning streak less probable (mainly for a lack of space).
The actual probability, imo, should be considered either by a simple pattern point of view and, more importantly, by certain quality factors prompting the hands formation.
In no way we could think to hope for a preordered amount of W units either per each shoe or per a series of shoes as we do not know how things will develop and the same is true about Ls situations.
Knowing that the actual shoe has a probability different from zero to produce all winnings represents a good start.
Conversely, cards distributions forming unlikely "losing" situations at the start (albeit due for obvious reasons regarding variance) are not going to produce specular winning counterparts.
It's like stating that key cards clumped toward one side at the beginning are symmetrically clumped toward the opposite side thereafter.
Of course people making a living at numbers like to wager toward the unlikelihood that something won't happen, thus betting toward slight or intermediate more likely situations.
And more often than not the initial-mid sections of the actual shoe are offering us good hints.