When you open a position, you might encounter with the amount limit. The purpose of the design of amount limit is to protect traders and LP participants especially when market is volatile. Here are some examples of these special circumstances.
Single order amount limit
For a single order to open or close a position, the amount of the order will be limited by following formula,
Single order amount <= Size of LP pool *3% / Index price
Net position ratio
For a specific trading pair,
Net position ratio=user net position amount * index price / LP * 100%
When Net position ratio < -R , no more new short position can be open.
When Net position ratio > R, no more new long position can be open.
There is no limit from net position ration when closing a position.