Hello Yannis; just some musings.
First, what do you refer to when you say Martingale? When you mean "doubling down" on even chances, or less than doubling down on less than even chances, AIM is not at all like the Martingale system. With the Martingale system (doubling down) you wait for a 100% gain on your last bet in the series to make a 100% gain on your first bet in the series. A gambler, who always has limited funds, is sure to lose everything this way sooner or later, even without the little tricks the casino uses to better the casino odds (maximum bet).
In gambling terms, AIM is more about bankroll management than about a betting strategy. AIM forbids plunking down all your cash at once, and only allows you to dive in deeper when the stock has become cheaper. It also forces you to take money off the table when your stock is winning. This has, of course, the (strategic) consequence that you buy low(er) and sell high(er).
Of course you may ask: "but what if a stock dives even deeper than my cash position for that stock allows?" Well, if that happens, your bankroll tells you that you made an error of judgment. The size of the cash position may be viewed as your estimate of the maximum amount that the stock will go against you. With the originally proposed 50% cash position, the stock may drop about 50%, with an initial cash position of 33%, the stock may drop about a third before all cash is exhausted. When it has become clear that you made an error of judgment, you should reconsider. What your conclusions then will be, will depend on a lot of things. But never should you buy more automatically, because "AIM tells me so". On the contrary, AIM says you have zero cash for this stock, so you CAN'T buy.
When you pick a stock for AIM (a decision AIM tells you nothing about), it should be a stock you want to invest in, not just a stock you want to make money with, because AIM was conceived for the long term. Then you should decide how big a position you want to reserve for this stock (again a decision AIM tells you nothing about), and then you decide the size of the initial cash position. A good indication for that may be Tom Veale's IW, but for riskier stocks you probably should reserve more cash. AIM takes it from there.
Of course, there are lots of other interpretations of AIM! Have fun finding your own way!
Regards,
Qarel
