If the parameters are too far out balance then trying to force the peg by spending money can be very costly, including by potentially ending up accumulating a lot of SBD that needs to be held without being adequately compensated for the risk it could fail. It also could tie up a lot of their money indefinitely that they want to use for other development purposes.

Where direct trading can work well is once the parameters are close to a good overall balance, keeping the price stable between 99 and 101 instead of what might be natural fluctuations of 97-103 or even wider.