as long you don’t explain before your buy order goes through
might even make sense to build this into the UI. noob-facing flavortext might be like “After-Trade Comment: make a comment that only becomes public after your order goes through, to explain your reasoning once you’ve bet on it? if you’re honest and correct, and others know that, others might match your bet, allowing you to sell early if you’d like to de-risk”
realizing that there’s still incentive for timeliness that might be awkward. it’s still the case that the person who trades last has the best position to update off whatever information the order book provides. This might cause people to put fake orders in and change them last-minute. possibly avoidable by, eg, limiting how often you can change your order; perhaps for a 1 day call auction, you can’t change your order more often than an hour after you placed it? perhaps this only makes sense for a limited period before the end of the call auction, eg if you have an order in the book 2 hours before it closes, you can’t change that order. that limits the time period where someone has to come back to check if someone did a fakeout.
alternately, just don’t provide any information from the unclosed call auction whatsoever; the price updates once a day, and you get no further information.
might even make sense to build this into the UI. noob-facing flavortext might be like “After-Trade Comment: make a comment that only becomes public after your order goes through, to explain your reasoning once you’ve bet on it? if you’re honest and correct, and others know that, others might match your bet, allowing you to sell early if you’d like to de-risk”
realizing that there’s still incentive for timeliness that might be awkward. it’s still the case that the person who trades last has the best position to update off whatever information the order book provides. This might cause people to put fake orders in and change them last-minute. possibly avoidable by, eg, limiting how often you can change your order; perhaps for a 1 day call auction, you can’t change your order more often than an hour after you placed it? perhaps this only makes sense for a limited period before the end of the call auction, eg if you have an order in the book 2 hours before it closes, you can’t change that order. that limits the time period where someone has to come back to check if someone did a fakeout.
alternately, just don’t provide any information from the unclosed call auction whatsoever; the price updates once a day, and you get no further information.