Hi Keith, It's rare that we have an event in a stock where we're flush with cash and the very first buy signal given by AIM is large enough to utilize over half of the total available cash. I think this is why "half way to the wall" isn't used sooner. It's there only to prevent AIM from emptying more than half the purse on any particular purchase.
If your account was 50% invested, 50% cash and AIM wanted you to spend more than half of that cash, it means that your stock has dropped tremendously. Holy Bouncing Cats and Falling Knives, Batman! Who Pooped on our stock???
AIM's proportional in its purchasing and selling. Large movements in price generate large trade orders. Small moves generate small orders (or possibly no orders at all if the price is still inside the Hold Zone). The more a price has dropped the larger the order size is going to be. When AIM's already seen several buys in a row, Portfolio Control is also contributing to the order size and pumping up the sales and cash burn.
It's very rare when we have a major index of over 3500 stocks fall ON AVERAGE by nearly 80%. Planning only for this sort of event is like carrying an elephant gun around all one's life, just in case you might have an elephant suddenly appear and charge. At this point, I don't see the broad averages falling an additional 80% thank Goodness! So, I'm going to clean the Elephant Gun and make sure I have some ammo, but it's going back in the gun cabinet, I hope for about 70 years.