How do I simulate a trailing limit order, since many brokerages don't offer this? Details:
XYZ last traded at 10 and I want to buy it at 9 or lower.
However, if XYZ rockets to 12, I'm now willing to pay up to 10.80.
In other words, I'm willing to pay 90% of the highest value XYZ has reached since I placed my order. This is a "trailing limit".
Many brokers offer "trailing stops", but few offer "trailing limits".
General idea: I don't want to miss out on XYZ's increase, but I also know stocks usually don't go straight up or down. In particular, I believe that if a stock jumps up, it usually comes back down slightly due to profit-taking, and I obviously don't want to pay the peak price.
Is there any way to simulate this kind of order for brokers who don't offer it? I'm actually trading FOREX, but the concept should be instrument-independent.