A lot of the old bulls say things like 'oh there's only 23c left...

A lot of the old bulls say things like 'oh there's only 23c left to lose while the upside may possibly be much higher' as a justification for remaining invested in what they freely concede is an increasingly risky bet

I think this is the wrong way to look at things. Each trade should be assessed on it's merits. Regardless of how much one has lost previously on the stock one should always try to maximise the value of what capital remains, including by selling and investing elsewhere if need be

As an analogy, imagine you are the leader of a special ops team and you have sent in ab elite squad (ie your capital) to extract a high value target (ie profit). The operation was poorly planned however and a large number of your squad were KIA!

Now, would you simply abandon the remaining survivors?? of course not. Unless you thought they could still successfully extract targets despite the circumstances that led to the demise of their conrades, you would extract them (sell your holdings) so they may be used in future (hopefully better planned operations)

Hope this helps