A large problem with limit orders is they can be filled by news traders, which lowers liquidity (limit orders) on markets. One possible solution is limit orders that fill at a certain rate of mana/time, to give time for the limit order creators to cancel their limit orders before the news traders eat the whole thing.
For example, in the limit order panel you could set a rate of 1k mana/hour fill rate for a 10k NO order at 80%. News breaks and the first news trader fills 1k of your limit order, moving the price up to 99%. Every hour after that, your limit order buys another 1k mana worth of NO shares to bring the market back down to 80%, unless you come in before the remaining 9 hours pass to stop it.
Pros:
Reduces downside risk of news trading to liquidity providers
Simple mechanism to implement, relatively easy to explain
Cons:
Limits upside if the trades aren't based on real news, and instead just wild swings from dumb money
Would you place more limit orders with this feature? Why or why not?
I feel like this might too easily allow manipulating a market's activity. I'm not sure exactly how Manifold prioritizes which markets to display on people's feeds, but I suspect trading activity affects it. A periodic filling limit order of '1 mana/hour fill rate to 0%' combined with another '1 mana/hour fill rate to 100%' would allow automatic bumping of a market at a cost of less than 50 mana a day.
Someone feel free to correct me if this kind of trading activity isn't relevant to the algorithm used.