In the balanced strategy, the target amount of the bid uses the following formula:
targetAmount = (2 * availableAmount * spread) / (4 + spread)
and then reduce it by 5%. If you have multiple bid levels, then the
availableAmount changes with increasing levels and the
targetAmount decreases. The
targetAmount for the balanced strategy cannot be controlled by any other configuration variable except the
spread. But, if you increase the spread, then your
targetPrice will also change.
For more details, see the code here.
As far as my understanding: If you want to control the order size, then you have to use the pendulum strategy. In balanced strategy, the mid market rate is obtained as
assetA / assetB. So, a larger bid size will shift the balance leading to unrealistic bids and asks.
Edit: I downloaded the source code and modified the balanced strategy to include a configuration flag
AMOUNT_MULTIPLIER to control the amount that Kelp bids. This is not suggested as it may lead to unrealistic bids and asks -- leading to significant losses in the market.