Your point boils down to "crap traders lose money".
Leeson lost money because Barings trusted him to not need any risk management, so he went and acted like a kid locked in a sweet shop. He was a poor trader who rose to a position way above his competence level.
As far as people buying a dying company down to zero, well again their demise isn't caused by the method, it's caused by their incompetence.
A strategy is only as good as the trader using it.
Virtuoso,
Marconi was a dying company, in hindsight, but, many reputable analysts were predicting the price to go above 1,000p. These people were not forum whisperers; they were working for the major stockbroking firms. Let's leave that aside, as it's now history.
I have no quarrel with scaling in being used as a proper strategy. Unfortunately, it is, potentially, financially damaging if utilised by the inexperienced. Nowhere is this more apparent than in the forex market. I was trading £/Yen, in July 08 @ around the 210 level. By Jan 09, it had dropped to 119. Scaling in would have been disastrous, without strict risk management
There have been some generalisations put forward but, nobody seems to have, specifically, given clear guidelines on how to use scaling in to it's best effect. I'll do my best to set it out, as there are inexperienced traders that may benefit. I'm a Spread Bettor so, I'll use that terminology rather than x lots to illustrate how scaling in works.
If my normal bet is £10 per pt., and I feel that GBP/USD is going to 1.70+. I'm convinced that this current move back to the 1.66 level is a pull back
. I have two immediate options (I'm disregarding Stop and Limit orders for this example). Firstly, I can make a bet at market for the full £10 and look forward to it reaching that level or, if the market has been quite choppy, I can scale in. I break my £10 stake into five tranches of £2 each. I place my first trade @ market (say 1.6650) for £2. If the price drops to 1.6625, I can place the next £2 and so on, until the 5 tranches have been exhausted. I pre-determine where my final SL is going to be and once hit- no more scaling in.
The benefits of the above strategy are that I will benefit from price moves above my entries and my risk is reduced because I am not betting the whole £10 per point in one go.
If I appear to be arguing against myself, that's not the case. I feel that most people do not know the difference between scaling in and
adding to losses hence the above explanation.