I can add liquidity to a market but the UI doesn't show how many of the shares I am currently providing on the table as liquidity, and doesn't let me pick them back up. I can close my market to take all of them off the table and that's a good start, but in particular once I've buttered a week-long market about next year and then closed it, my liquidity shouldn't stay locked up for the duration.
Withdrawing liquidity is technically simple, if the implementation is as I expect: You take (one third of, one half of, etc.) the shares you own on the table off the table, keeping the market probability constant. If that probability is different than when you staked liquidity, you will end up with leftover shares, which you can keep or sell - that sale will of course move the market.
You could, if you like, allow entering negative numbers on the Add-Liquidity form, so long as the limit orders you are implicitly offering at every market price remain non-negative.
Martin Randall bought M$10 of YES18 days ago
It's a good idea. How would it work with free markets? Would there be a minimum liquidity?
Ending up with shares could be awkward because it could increase perception of self dealing.
Daniel Reeves bought M$1 of NO18 days ago
Gurkenglas has convinced me that this makes sense, and I like the idea of just allowing you to put a negative number in the add-liquidity form. You could let the feature be a bit easter-eggy at first. It all makes mathematical sense, I believe.
S G bought M$1 of YES23 days ago
I'm thinking about it...I think this market is accurately priced right now though.